It all depends on the race and/or track. You will need to visit the track you plan on racing at to see what they have. The above electric classes are usually broken down into 2 wheel and 4 wheel buggy, and 2 wheel drive truck. In addition to those electric classes there is also:

Gas Truck
1/8 buggy
Super Monster Truck
Truggy

Novice classes can be seperate, or even 'run what ya brung.' In otherwords novice drivers are thrown together regardless of what they race. But every track and race has its own rules.

Then there is also On-Road racing. Outdoor on-road is far less popular (tracks are super expensive), and indoor on-road (carpet racing) is a horse of another color. You don't find as many novice classes here.