Adding new tires/rims -alloys on my car!!!

hey, just a quick question i have a car with 14inch tires or rims i think i don't know much about tires and rims all i know is that on the tire it says R14 so i was told that means its 14inch and i just wanted to know dose anybody know what size rims i can buy that would fit my car??? like does it mean that because i have 14inch stock tires i have to buy 14inch rims? or can i go up a few??? please reply thanks