How are the races setup? Is it based off of time or first person cross the line win?

You want to get the fastest lap time. The race ends when the winner completes their final lap.

Winner is based off time. You get 12 laps on the weekend and the first two laps are warm up laps. Expect at least two spin outs effectively cutting 12 laps into 8 real racing laps. And that equals about 4-5 mins of race time. Not worth it!

You all get to circulate at the same time, then once the fastest person has done their laps, everyone completes the lap they are on

Its based off time

You get to race together but winner is determined on time