Definitely master offline first. If you can win on Phantom Elite by 1 second, consider that the average Phantom class pilot online will probably own you by about 10 seconds or more. Online requires different strategies, and a lot of pilots don't use weapons, rather absorb everything to make barrel rolls and shortcuts. The Elite AI doesn't do this.

Find a style that suits your personal play style and commit to it. I'm a green racer myself, so I'm quite vulnerable to a weapons tech pilot. But if a green racer gets ahead, don't expect an entire army worth of weapons to make any difference.

Also, don't get discourage by online mode. You learn really fast. Look for the best pilots, and race them. Slower pilots don't test your skills and the only way to get better is to race against the best.