Do girls prefer movies with friends or movies alone (with you of course)?

Well depends the girl.
my mom makes me do double dates.
but I've done alone dates. Sometimes
girls would prefer double dates because
they don't want you to take advantage, but
some like making out and other stuff.
so just ask her what she would want to do.

I believe that she would definitely want to take her friends on her first date and you should take some of yours too.