if there was a show like stars in their eyes and people dressed up as a singer can a girl dress up as the 80s boy george
It is not illegal for a girl to dress up like a boy.
It is not even that unheard of. There are movies that portray girls dressing up as boys. A movie starring Barbara Streissand-Yentl, was critically acclaimed, and Ms. Streissand was Yentl, a boy.
The only think keeping you from dressing up like boy George and playing him in any venue is your own concern. Just do it. Nothing is going to stop you, you won’t be arrested, and you may be good at it.
Just go for it!