New to race leagues

Hey good people, I am just starting my race league career. I have been put into the grassroots league. so the first series here is Modern Sprts Legends league. so any good cars I can take out on this series, as well as tips to a good tuner?

I currently only have one eligble car the honda nsx r. but would like a little bit more choice in cars. so any advice or tuners I should look at for this series?

Thanks Phred.