Follow nubs advice for the draw length or go to a pro shop and they will help you figure your correct draw length.
If you are serious you should save up your money and get yourself a quality new bow. GO TO A PRO SHOP, starting out on your own is like kicking yourself in the butt. They will give you good advice and will be sure that you will get everything that you need.
Good luck and do yourself a favor and save up your money and get a good bow!