momaxx, to make your own tracks from scratch you must have RealRace G2; the first version of RealRace does not support custom tracks.
You posted this message in the RealRace Classic forum, so I'm guessing that's the version you have. If you already own RealRace Classic, Duratrax is providing a free upgrade to G2. If you send in your Classic disk and $10 for shipping & handling, you will receive a brand new RealRace G2 disc! For more details, email email@example.com.
If you do in fact already own G2, refer to the manual that came with the program (it will be located in your RealRace G2 directory). There is an entire chapter devoted to custom track creation!