Your first sentence has some odd wording: Do you mean you are new to
RPGs in general, or new to being a
GM?
Either way, it'll work if you keep the basic stuff in mind. My usual advice:
* The player characters are the stars. Not the most powerful characters, but the most important. If stuff doesn't involve them, don't worry about it (and feel free to fake results for dramatic effect).
* You are not the adversary of the players. You are there to make things cooler.
* Establish some boundaries and expectations with the players. I'd suggest stating that you want to keep things simple at first, so sticking to the main book (+ errata, if there's anything big). You DON'T need to worry about adding in the books to add xeno characters, characters from the sister game lines, or other advanced options. Save these for later. Also set up if the game is intended as an open sandbox (players do what they want, the
GM just responds), plot driven (There's an overarching plot the players will need to constantly deal with) or a hybrid. Make sure they know if it will be combat heavy or diplomatic
* Remember the whole "it's a game" thing.
For some specific advice, I have read
RT but not played it. Compared to other
RPGs, the big 'hook' is some neat looking rules to abstract out trading and ship operations.
Your best bet may to look at the adventures
FFG has published and pick one of them as a starter. You can rewrite and tweak as needed. The published adventure may supply some basic hooks to use so your players can get into the 'system' the game provides where they get points for doing missions they can sue to upgrade the ship and their personal gear.
In general, don't sweat the small stuff. Running a combat or two with a smaller group is a good idea: Grab pre-
gen characters (or make some quick) and play out a combat so you can learn the basic game flow.
RPG players get attached to characters, so it's best to try out combat on more expendable characters before a rules mistake leads to the death of a character they've invested time and effort in.