OK my friend told me that she might be pregnant but doesn't know if she even had sex!! Her and her boyfriend got WAY to drunk and when she woke up her pants were undone and pulled down and so were her bf's. What should she do??

Has she missed her period yet? If not, I wouldn't worry too much yet. It could be a simple scare. If she's missed it, she needs to get a test. Home tests work just fine, and are inexpensive. First morning urine works best.
Just because their pants were down doesn't mean she had sex, but it's a pretty good guess that something happened, and penetration doesn't necessarily have to happen for pregnancy to occur. Pre-ejaculate fluid from simply rubbing genitals together has caused pregnancy without penetration, though it's rare.

May be she should give up drinking. Unfortunately the only thing you can do is wait till she can take a test