From my experience as long as you keep your teeth well away from his pride and joy your good. Like all things every guy has different likes but unlike us girls they seem to be more comfortable asking for and telling you want they enjoy

As for the act of giving oral sex you might find practising on a popsicle fun and you can get him show you his technique Sex doesn't have to be as serious and intense as Hollywood portrays, some of the best sex I've had I giggled the whole time.