Some things to consider:
If he insists on buying all of your movie snacks, it very well could be a date.
If he insists you sit in the back or in a more private area.
If he seems overly giddy about being out on the town with you then its probably a date.. lol.
Now if he's nonchalant about the whole thing then its probably two friends meeting up to do something, but when does that happen really? I have never been out with just a single friend and I.. well one that is straight.. lol.. but eh.
Importantly though, don't make the situation strained by asking tons of questions, you don't have to do anything spectacular, usually if you do ask questions or insist on gestures then it turns messy or at least an outcome you don't really want - or do you want it to be a date?