I am far from an expert on this matter, but I'll give you my humble opinion.
I think it was just fine that you invited him for a drink. It shows him that you like him, at least as a friend to hang out with...and who wouldn't like that?
Since you have made the first gesture by inviting him out, and since he didn't show, I would say lay low for a little while. Continue to talk to him and flirt with him as you have been so that he knows you like him and that you aren't upset that he didn't show, but don't ask him out again...for anything. The ball is now in his court. So give him a little while to play with it. If he doesn't throw it back within several weeks, then you can try again.
