Soo I just got asked out a few days ago, and I didn't
Know that my best friend like's the guy I am dating!!
I don't even think Ilike him, and I have no clue what to do
And how to resolve this!

There's nothing to resolve.

You can't apologize for offending someone based on secret info. That's nuts. So ignore your friend's "hurt feelings" over it, it's not your problem.

You can date whomever you want and you can stop dating whomever you want. You say you got "asked out" only a few days ago, then immediately call it "the guy I'm dating"... you're talking crazy. You aren't dating him, he asked you out and you may or may not have gone out with him... you didn't say. You aren't "dating" yet. So, when he calls and asks you out next, simply decline.

"I appreciate your interest, but I won't be going out with you privately anymore, I'm not really interested in you that way and I would hate to waste your time or money. I'm sure you understand. See you around."