Is it okay to go alone or just with friends?

It is perfectly fine to go to prom without a date. In fact some people even prefer going with a group of friends because it means they can dance and mingle around with whomever they choose and won’t feel tied down the whole night. No one will judge you for not having a date and no one will probably even remember. It is your night and as long as you are having a good time that is all that matters.