i am making something similer and im also a little new to this as well. but i think i maybe able to help you. in the AUM magazines article 32-35 as a tutorial of a car racing game. in there you can find out how to have you bike ride on random on its path.

by any chance would you know a script to make the user car or bike accelerate?
(this where i am stuck in my game)

thanks

-Marc