Not to regurgitate what's already been said but-Here's a simple step by step guide to getting some condoms
1) Get some moneys.
2) Go to a store that sells condoms.
3) Find condoms for your size(normal or w/e usually fits most)
4) Proceed to buy condoms.
5) If the clerk is a complete douche and won't sell them, reffer to step 2.
It's actually quite simple.. Or you can always go to the local health clinic. They give 'em out for free.