How do I become a femboy without my parents knowing?

Grow up

You are born male - be male

If you are homosexual be one but don't tryand puh this on to others as others may not have the same point of view

If you want to be transsexual then think long and hard about that decision before you do something. It may have consequences 10, 20 or 50 years on that you can not undo what you may have thought was trendy now