Don’t go buy some huge breast forms and look like a porn star, don’t live the pre-existing stereotype people have already about crossdresser. Find forms that look and fit your body type. Most crossdressing girls fit into the B-D cup area. Just remember forms need to be proportional to YOUR body, so if you have a few extra pounds and are taller, the larger DD cup forms may look more natural than a smaller B cup form.
Forms can be found all over the internet, and can be sized by cups, or by grams. I have D-cups/1000gram forms okay so use 1000 gram (D-cup) forms. The D’s are just a hair “chesty” for me. I do use my C-cup/800gram forms to sleep in. I do enjoy the C cups too, but D’s are just a lot of fun sometimes too. I’m 180 lbs and 5.10″ So I think you may want to google some female pics that fit your size and shape to see what you like and head that route.
Breast plates are a lot to deal with if you’re just staring out. They are also hot and sometimes a pain to put on flying solo.
PS- use the search button in the upper right hand of the screen! This is a topic that has been talked about many times over. But we are still here to help!!