Well, you can either enjoy the racing or try to get out quickly by starting in pits and following the fighting grid at a safe distance. This will usually produce a) not much close racing, b) the mandatory results to get out of Rookie. Your call.
To start from pits, simply do not join the grid during the two min. prep time but only after the starting lights have come on. You will be sitting in your pit stall and a counter at the top of the screen will count down the 15 or so seconds till you can start. Watch out for pit lane speed limit, though, it's already active an the Rookie cars don't have a limiter!
Also, before any start in the lower classes, set your fuel intake at pit to zero and unclick your tire change (F4 and F5 screen), that way you will only get the quick repair if you are involved in a crash and not the normal pit activity on top. Quick repairs are non-existent in the higher classes, though, but this procedure still makes sense because it cuts down on pit time after a crash anyway.