dan is 1,000,000% correct. IMHO, if you can't pay cash for something other than a house, you shouldn't be buying it. When you borrow, you pay more for the item than its really worth, and in the case of cars and cycles, they simply depreciate making the whole situation worse.
Buy used, in cash, to start. Good starter bikes go for $1k or less. And I'll hazard a guess that if you're borrowing for the bike, you have no gear whatsoever, making your situation even worse. Don't skimp in this endeavour, you'll be sorry.
Credit cards are how I started out, with only one, and now I have a stellar rating. I have never missed a payment or been late; in fact, I've never not paid the balance. If you start using it frivlously, it will take you a long time (think years, not months) to get your credit score back in line with average, and this will hurt all kinds of things:
1) Some insurers' quotes
2) Future credit-based purchases, like a house
3) Job opportunities (some, not all)
Credit is being used in settings you'd never imagine, so fooling with it can be a real strike against you.