Tell me how to have a girl voice

Work on moving your adam's apple up and back.

Up, but not into falsetto range. You just want to get into the standard deviation for feminine pitch. Yes yes, there are women with lower pitches than that, but you don't have the luxury of not fitting in with important aspects and still being seen as female. Suck it up and raise that pitch.

Back, so it goes into your throat. Not so much that it restricts your ability to breath and speak, but there does need to be constriction.

It's a lot of muscle control, and it will get sore at first. If you experience sharp pains, stop for the day so you don't fuck your throat up like the dumb tranny you are.