Ummm, why do you need to make it faster?  If you really think you need to
the easiest thing is just put a turbo on it.  A lot of people like to swap
out the 2.4 with an SR20 but for your first car I wouldnt bother.  To tell
you the truth I'd look for a 240 SX if you want a fast car.  As for looking
nicer just some aftermarket rims adn tinted windows look nice IMHO, a
bodykit would be nice if youl ike that sort of thing, check ebay for altima
bodykits.