Doing both Campaign modes is the most sensible start IMO, then mixing some Racebox with some online races and some trophy hunting. Just taking your time and having a go at everything really.

When I think how hard WOHD was at first it's ridiculous. the last Wipeout game I'd played was Fusion, which I was very good at, but the difference was astounding. I was crashing all over the place and struggling against Novice AI on venom.

It's just practice, plain and simple, and taking the advice of more experienced players. The Youtube vids / tutorials help greatly, they show you what's possible, even if you'll never master some of it.

Edit: Oh and I've been chatting with some of the new players online. Some of them are really keen to learn and are already falling for the game. I've pointed them in the direction of WipeoutZone, hopefully some of them will come.