Asked to Snowball! Help!

Hello. So there is a dance on Saturday at my school. This boy I've had a somewhat off-and-on crush on asked me. I said yes. I am super socially awkward, I always feel that people are judging me. So I know we both will be nervous. I don't even know if he really likes me or he just had no one else to go with. Any suggestions, relationship advice, or tips. Anything is greatly appreciated. (Also slow dancing is going to be awkward he is much taller than I am.)