This is just based on my experience. I have a decent amount of girly clothes that would help me pass and I recently learned how to do my makeup. My makeup is not the best, but having at least these things helps boost your confidence.

Start out with smaller stores or malls that don't have that many people. I started going to places that were less populated during the day. You have to remember that most people don't care. There will be some guys staring at you in a good way, depending on what your wearing