I'm fairly new myself, only had LFS for a week or so. I've been playing around on the STCC New & Bronze server and so far haven't had any trouble, even though I'm usually 2-4 seconds slower than the leaders (*sigh*). As long as you obey the blue flags and don't take out the lead lap cars, you'll get along fine and learn a lot, plus the license program gives you something to work towards.
Maybe practice with the UF1000 in single player race/hotlaps for a while to get a feel for it before you go online (try some different setups, too). Once online, if you don't know the track, go into spectator mode and follow along with one of the leaders until you feel comfortable giving it a shot.
Good luck.