Well, off the top of my head I can’t think of anything that would really be equivalent to a ‘prom’ in the ancient Greek world (or even the concept of dating, for that matter), but I guess you could just call it, like, the Dionysia or something; that’s probably as close as you can get. In which case, something like:
ἆρα βούλει μετ᾽ἐμοῦ πρός την Διονύσιαν ἰέναι;
ara boulei met’emou pros ten Dionysian ienai?
(N.B. if you’re writing this out, standard Greek orthography uses a semicolon for a question mark.)
Pokémaniacal 