What to do about this guy...winter formal?

So I asked this guy to sadie hawkins winter formal but I don't know him well. He's shy and we'd been smiling at each other for months so I figured I might as well ask him so I can get to know him (because I was too intimidated to talk to him otherwise)! We haven't bought our tickets yet but it's on Saturday and I got invited on a limo today so there's that option. However, that might be expensive so I could have one of our parents drive us. I just don't want it to be awkward all night since we aren't close yet. Or, I could ask him out somewhere else (I was thinking since we already have our formal clothes--or at least I do...I forgot to ask him but I'm pretty sure he does--it would be funny/cute to go out somewhere not so fancy in our dress/tux). what should I do?