<human>: Hi. So I'm 18 and pretty much fresh out of school.
I've already got a decent job, with little overhead expenses (rent to parents, car insurance, gas, food). I really want to think about my financial future, and I figured; why don't I start building credit? Now, something I'm going to purchase when the cold weather passes is a brand spanking new motorcycle. It's MSRP is 5,200 or so before taxes and fees. I was originally just going to buy it all outright, but then I thought about building credit.

How should I do it? Should i put down $5000 and spend 24 months paying off $200? Or would I get far more credit rating by putting down less and paying more per month (with a regrettably higher interest rate)

Also does the length of time effect the credit rating I gain? I'd much rather pay off for 12 months than 24 months if it's such a little amount.

Can you summarize the given text in a few sentences?
<bot>: I'm young and don't know how to build credit, making a credit-building purchase soon, how do I make it worthwhile in the long run?