Your simplest solution: stop DMing and play for a while
You have two experienced players, you are new, and there are new players, yet these two experienced players (rather than offering to run a game and introduce some new players to the game) rely on you to be the DM. While that is not necessarily a pernicious situation, it can be and you have run into why it can be hazardous.
Pile on top of that, as other answers have pointed out, your choice to vary from core game rules ran into friction because Home Brew is Hard To Do well. You made a mistake that is easy to make; been there, done that, got the t-shirt. From comments moved to chat:
Well the problem is that its homebrew. I followed the lead of another
player who ran a campaign before me. He changed a lot of the rules and
when I tried to introduce the actual rules I kept getting "well its
homebrew" so I am stuck in an impasse.
If I can post a homebrew here, and have lots of holes pointed out, with my experience as a DM and in this edition, what were the odds that your house rules were going to go off without a hitch? Small.
Your two experienced players aren't being good at mentoring you, a DM who is new to the game. And, they imported an overpowered item into your game ... Red Flag. I've been seeing stuff like this since old school D&D and the standard response was then, and ought to be now: "I don't allow that into my world" - but how could you know that it was "off" since you were new, and a new DM, in the first place? I suspect that at least one of these importers was taking advantage of you.
As to this, the blind leading the blind:
I followed the lead of another player that dmed within our group. He
didn't have the actual rules on hand and made a lot of stuff up as he
went. To the point that when I tried to introduce actual dnd official
rules to the game they said they didn't like them. I'm realizing now
this is where to problem originated and i'll need to sit us all down
and go over the basics or step away from dming because honestly it was
fun at first but now its to the point where I'm ready to jump off a
Your whole group needs a Session 0 to get the Basic Rules out and see how the game works. A Session 0 (the link for how to DM one is here) can be done any time a table needs to reboot and to get on the same page.
He found the armor in another player homebrew campaign and brought it over. It had a higher armor rating than d&d allows I know this.
With friends like that, maybe find new friends? Or, invite them to sit in the DM's seat since they aren't happy with you in it.
How do I do this? ?
Learn by playing.
Tell the table, old and new players alike, that you want to step down from DM'ing for a while and play. Then ask one of the two experienced ones, with all present, if they'll volunteer to be DM. Yeah, they are kvetching about your DMing - OK, call them on it.
Your message needs to be, in your own words:
"Show me how to be a better DM by demonstrating. You DM for a while."
You'll want at least five sessions where one of them is DM. Insist on it.
Why five? You'll want to see a variety of situations and scenarios and how they get things to flow. You'll also begin to get a better feel for how a character grows, as well as how to try and apply features, skills, spells, etc from the player side. And the costs of choices.
Don't homebrew until your expertise improves
As with jazz musicians who improvise, the really good ones are already expert at playing the music, and then they depart from the script. Likewise with some of the brilliant guitar players of the rock era. You haven't got that level of expertise yet, so I'd suggest that you rely on "what's on the tin" - just play the game based on what's in the books - until your depth of expertise in this system improves. Stick with what's in the book and only improvise where the book is silent.
Why are you telling me this, Korvin?
Because I was a novice DM once too, a long time ago, and I ran into stuff like this. Also, playing will help you to learn the game better, and as a result you will be a better DM the next time you sit in the DM seat.
Anyway, your question was "How do I handle these players" and my core answer is "play more first to gain more system experience." But that's only part of it.
Based on what you shared in your question, you are already about five steps behind the people you want to "handle." Old advice from my tennis coach: never change a winning game plan, always change a losing game plan. Your current line of approach is the latter.
That's my proposal to you for fixing what I think is your actual problem:
(a) two experienced players aren't treating you right, and,
(b) you are trying to improvise before you have sufficient systems mastery.
Crawl, walk, jog, run, sprint
Good advice in a lot of pursuits, to include being a DM.