I DON't KNOW HOW TO GET INTO MY IPHONE 4?

A friend gave me his iphone 4 and i decided to reset it so that i could restart it so it was like brand new. Once i reset it and started setting it up, it told me i had to put the apple id & password that the phone was originally set up with. Problem is the friend who gave me the phone doesn't remember that apple id and password so now i can't even get into it! WHAT DO I DO? I just got it now i can't use it

Take it to the Apple Store. They can fix that.

Apple can fix it but only if you provide solid proof that you own the phone. You won't be able to provide solid enough proof, but your friend may be able to if he's willing to do so.

Without it the phone is just useless junk. There's no way for you to bypass the Activation Lock.