My guy friend asked me out but I'm unsure of what to do?

Well this is the first time ever something like this has happened to me. Me & my guy friend (lets call him Ryan) were texting a few mins ago & he basically asked me out on a date. He has said I have become prettier & all(which yes it's very nice of him) but since this is all new I panicked. I text my bff(call her Ana) & told her about the whole thing. Ana said "ewwwww he is a creeper & stalker! Nooooo!" (Which I admit I've known Ryan since 10th grade, he is going to be freshman in college while I will be a senior, he is the biggest flirt I've ever meant, luvs making pervey jokes & he makes me uncomfortable & nervous) He can be a nice guy but I'm nervous about all of this. He has asked me to hang out(not in a date way) many times before but I have been very very busy with school & work. I would really love some advice from anyone. Thank you guys! P.S- I asked him after he asked me out if it is ok if I think about it, since this is all new 2 me. Was that an ok response? he wrote back "No worries :) Good Night & sweet dreams".