I'm a freshman boy and I don't have a date to prom how can I get one

Usually prom is just for juniors and seniors so freshmen boys don't generally go. If freshmen go at your school, what you do is choose a nice girl who you know and who makes you comfortable, who you would like to date, and you walk up to her and ask her if she'd like to go to the dance with you.

She might say "no" and if she does, you can ask someone else.