Do you have a specific question about this? The main issue is with Rosalind who disguises herself as a boy and travels into a forest where she meets Orlando, a man who fell in love with her before but does not recognize her as Rosalind because of her disguise. Disguised Rosalind then pretends to be a girl to role-play with Orlando about his feelings toward Rosalind. So you have a woman pretending to be a boy pretending to be a woman.
What complicates it even further is that, in Shakespeare's time, female parts were played by boys. So, originally, the audience saw a boy pretending to be a woman pretending to be a boy pretending to be a woman. Yeah, it gets a little confusing but it works in making great theater.