hey what's up, welcome to the forums. i'm looking forward to seeing your firstp rojects, did you try out the trial/demo version of 3DSM before you bought it, so you might get an idea of about how this 3D stuff works?
i hope you will have good experiences in the 3D world
and modeling your own car is a good logical first step, you will be able to check every last detail for reference, it helps a lot