My advice to you is to start much smaller. Don't worry about setting up a campaign. Worry about setting up the first adventure. The best campaign will die if the first adventure isn't a lot of fun for everyone.
My other bit of advice is not to pitch a "free-trader" game that begins with the players being stuck on a planet without a working ship. "Free-trader" normally conjures up images of flying around space. You're also assuming that they are going to be interested in getting their ship back, but they have no attachment to it or anything else in the game yet.
If you want to start them with a damaged ship, that's cool. Start them off in their ship right after a sneak attack has disabled their jump/hyper/warp/go-fast drives. Give them a clear obstacle: some dudes are trying to kill us! Followed by a longer-term goal: we have to fix the ship!
And be sure to give them a place to go fix the ship: a planet nearby. Then you get to have the ship in dock, racking up fees and waiting for repairs. And then they can start looking for ways to earn that money.
It wouldn't hurt if their ship is totally sweet, too. Nobody is stressing about fixing up the interstellar version of a Ford Pinto, but the Millenium Falcon? YES!
My final piece of advice to a brand new GM: it's very easy to get in the situation where you've prepared something for the players to do, but they either don't know it or aren't that interested. And then you find yourself working on ways to make them go where you want them to go ("There aren't any other planets in range. There's only one city on the planet. There's only one spacebar. And there's one alien offering a paying job.")
Instead, this is how you should do your prep: at the end of each session, ask the players what they intend to do next. Whatever they tell you, prepare for that. If they don't want to repair the ship right away, don't waste your time pushing them in that direction. Maybe they want to explore the planet first. Maybe they want to establish a home base. Or take down the local corrupt officials. Or go hunting wamp-rats. Find out what that is, and prepare that stuff.
Make sure you let them know that it's their job to tell you, honestly, what they want to do as a group next, so you can run the game and everyone has fun.
p.s. When you prep that stuff, of course you're going to put stuff in there you find fun. You're a player and deserve to have fun too!