Most fellows aren't that great at using their hands - they tend to think they need to saw away in and out as though the fingers were a penis. Your best bet is to take his hand and show him how you masturbate - and, of course, he needs your lubrication or some KY or something because dryness will definitely hurt.
He knows you're inexperienced, so ask him to guide you in masturbating him. It is mighty nifty - especially when you're rewarded with an orgasm
As for going down - don't let others' opinions sway you. A lot of women love doing it and think men taste great. And the fellows love it so!