After you've gotten your safety gear, read up on the subject of motorcross and decided you want to learn to ride, you need to learn a few basic techniques.
The position of your body is all-important. Your center of gravity depends on where your body is in relation to the bike. You need to move your body for jumps, turns and hills. You need to stand at certain points and sit at others.
The other important technique you need to learn when racing motorcross, is your proper braking techniques. Motorcross bikes use front and back braking systems. You can learn to corner, jump and whoops by using your brakes. New riders depend on their brakes for controlling their bikes in the beginning, as they learn new skills, motorcross riders learn that they can use their brakes not only for basic control, but for jumping and other cool tricks.
Your track conditions determine a lot of how you're going to ride. If the tracks are rough, muddy or sandy, obviously your motorcross riding style will be different from a track that is hard-packed or marbly. You'll do less leaning on your motorcross bike when you corner on harder tracks as they tend to be a little more slick and you don't want to shift your center of gravity when you don't have the best in traction or your motorcross bike can simply shoot out from underneath you.
Speaking of cornering, that is another technique you need to master. You need to know when to sit down, lean, stick your leg out, accelerate and the right time to brake.
Jumping is on the most fun aspects of motorcross. Practice your jumping before you race, in the middle of a track is not the time to get brave and try out your jumping skills. Start small on a practice track and learn when to jump small, as time goes by you can jump higher and longer.
Motorcross is a fun sport and with a short list of skills, it can be an amazing ride!