KISS-NESTT
(Keep it simple, stupid-- no, even simpler than that!)
Dungeons and Dragons is a complicated game. I think it's easy to forget, knowing that 5e was simplified so much from earlier editions, that it's still got a ton of moving parts, and it can be immensely overwhelming to get started.
I've DMed for a variety of brand new players, some of whom were only obliquely aware of the game before I offered to run a little oneshot for everyone.
So, let's walk through the process I use to get new players up and running.
Character Creation
Make characters for them, or whilst sitting next to them. Character creation is an enormous hurdle in D&D, and it's made more difficult by the fact that a new player likely has no idea what they want to play as or what play style will mesh with them.
If I'm making characters for them, I try to pick simpler classes and generic fantasy archetypes, so that anyone who has so much as heard of Lord of the Rings will be able to figure out their "role" in the party. I mostly do this for family parties, where some of the players will understandably be more enthusiastic than others.
If I'm having players make their own characters, I ask them first what sort of fantasy character appeals to them (Do you want to be like Legolas? Arya Stark?), and then steer them towards a race and class combo that I think will fit their wants. Again, this is for a oneshot, so it doesn't matter if they don't wind up loving the character.
Then, I sit next to them with the Player's Handbook open, and we make the character together. This means I'm there to advise and guide them to the bits of information that are relevant to them. D&D can be a firehose of information if you don't have a guide; helping players skip over irrelevant nuances or overcomplicated spells mitigates this a lot.
I always roll stats with a new player. Why? Because rolling dice is fun, and it takes a long time to get to the point of having fun in D&D, especially the first time you play. Monkey brain likes seeing numbers that are big! Monkey brain likes throwing shiny math rocks around! Feed the monkey brain a little bit during this prep phase. This bit of advice is answering something that seems implicit in your group giving up on learning the rules: they gave up because they weren't having fun!
In my experience, around half of my players will want to build their own character, and half are happy with a pre-gen. Sometimes, rules-based questions come up in the process of character building-- either specific to the character ("What's inspiration?"/"What is this Hellish Rebuke thing and where is it explained?") or more general ("What is the difference between a bonus action and an action?").
In either case, this has given me the chance to explain that rule in context, to a person who actually thought to ask. I don't want to get too deep into the theories about how humans learn and the best ways to teach people, but a question that's asked in context is frequently a better learning opportunity than an answer provided to someone with no idea what question would even necessitate it.
Pre-Play
I employ a strategy similar to the one suggested by @Devin-A-Poet, but even simpler. I give the players a simple rundown of how the game works, with the steps listed in order.
- You, the player, tell me, the dungeon master, what you would like to do.
- I will either tell you that you succeed, or will ask you to roll a check. This will involve rolling a 20-sided die and adding a value from your character sheet to it. I'll tell you which value will be added.
- You will roll for that check, and tell me what number resulted.
- I will tell you if you succeeded or failed, and narrate what happens next.
Like I said: keep it simple, stupid-- no, even simpler than that. We are paring D&D down to its barest essentials. There are things that don't fit into this ultra-simplified description, but guess what? I can (and will) explain those on the fly, because I know the rules, and can clarify what's going on.
I make sure to both email these dumbed-down rules to all players before the game, as well as providing a printed copy to each player. Many games with complicated rules for the order of play do this; Castle Panic is just one that comes to mind, but I suspect it isn't the only game to do so.
I've found that providing this guideline to players has gotten them more engaged and more likely to take the lead when compared to the group where I didn't do this. Setting up the explanation of the flow of play as being player-initiated helps to get them moving.
Play!
Your players say they learn best by doing, and honestly, with D&D, I think most people do. So... get them playing! Don't dive in with your full campaign. Do something short and relatively fluffy, so that they get the feel for the game.
You're going to be fielding a lot of questions in this session. Many of them will be stupid. Answer them with grace and ask players to take notes on what's happening to clarify for themselves later. Some players do this on their own, but others might need a reminder from you to jot down the information on the appropriate part of their character sheet.
One of the most frequent notes I see people making for themselves is about the difference between rolling damage and rolling to hit. Yes, I could explain the difference before the game even begins, and sometimes I do, if they ask why their weapon has so many numbers next to it. But when I've done so, I can see their eyes glaze over in confusion; they don't know the use case for this set of numbers!
What happens the moment you start playing is that the players have context. All those rules fit into the flow of a game; the numbers aren't just statistics on a page; the spells aren't just convoluted text. The next time they try to read through the rules, they'll know what they're looking at, and why it works the way it works. The next time they go to make a character, they'll know what they liked and didn't like about the last one.
I've fielded questions from various players on this sort of thing-- one who wasn't sure she liked playing a bard, since she didn't love being a support class; one who wasn't sure he was loving his wizard and thought a bard might work better; and one who wasn't thrilled about his paladin's damage output and was trying to pick better spells for the future. (Yes, in my experience, spellcasters cause the most confusion.)
In each case, once again, they had context for the answer I was going to give them, making it much easier for that information to actually stick. They understood what they didn't know, and knew where to seek that information out.
I do advise lending your players dice, or having them purchase their own (if they've got the $8 to spare for a basic set at their LFGS). The physical act of rolling dice and the anticipation of the roll is part of the fun, and the tactile experience can help to get them engaged-- at least, it worked that way for me! (I will freely admit that two of my players were young teenagers, but the various parental units in their 50s, as well as the grandmother of teens, also seemed pretty happy with their "props"!) Again, as above, this is about making things fun for the new group. After all, why would anyone bother learning a complex set of rules for something that isn't fun? Make it clear that it'll be absolutely worth their invested time!
Post-Game
You asked, "should I let them know how much it's annoyed me, and reiterate they need to know stuff, or just ignore it and carry on?"
The answer is: Yes. Both.
If, after explaining the rules in the first session, they don't seem to be interested in learning the rules, they don't note down corrections or explanations of confusing mechanics, or anything else that indicates that they're lazy players who refuse to learn the rules: yes, you absolutely should let them know that it's frustrating.
Players who don't know the rules and don't make a good effort to learn are frustrating, both to the DM and the other players-- they're taking up valuable game time by not being on top of it! But there's no way of knowing if this is what's happening with this group until you've been playing with them for at least a handful of sessions.
I have, thankfully, rarely had to deal with this as a DM; normally, after I explain the same rule to a player for the third time, I'll ask them to make a note of it, since it seems to be a confusing point for them. This is not a time for being confrontational! This is usually worded as a friendly reminder using my best teacher voice, and has been pretty effective at preventing me from having to have more serious talks out-of-game.
But I try to give people space to figure out what's happening, and use my best judgement to decide if someone should've read closer or if it's just an honest mistake. Constantly having to remind someone how to make a spell attack is one thing; someone who misunderstands what the spell Chill Touch does is quite another. I try to err on the side of being lenient as much as possible; it's a game, not homework, no matter how much DMing can feel like being a teacher sometimes.
Final Thoughts
Learning something new is hard, especially when it is utterly unfamiliar to the learner. I think many adults have forgotten what it feels like to have to learn something completely new! And make no mistake, tabletop games are unlike anything else that most adults have done. Unless they've played another TTRPG-- perhaps even a D&D edition of yesteryear-- or video game RPGS of a very specific time frame from a very specific set of developers, they have essentially zero context for any of the new information they're trying to take in.
(Trust me, the difference between my dad, who has a terrible memory but played a bit of 2e in college, and my other family members who had zero context for the game is immense! My dad picks up the mechanics far faster than the others, although it did take a bit of persuasion for him to believe that being a paladin could be fun now.)
Be patient, simplify as much as possible, and have fun!