Some computers have USB ports on the front and some have USB ports on the rear of the computer. Depending on where your computer's USB port is, you may need a short USB extension cord to make your port accessible. Many Jump drives include a free short USB extension cord.
Some very old computers don't have USB ports at all, but you often can install (or have installed) a card that adds USB ports to the rear of your computer.
if your computer has USB ports, but they're being used by your printer or other devices, you can buy an inexpensive USB hub for about $20 or less that will allow you to convert a single USB hub into multiple ports.