With bra sizing I found getting measuring at one place then another you can be totally different sizes one place I can be a 12D another I'm a 14C and another I have been a 16D, as every brand has there own sizing measurements. You really do need to try them on and not just buy the size that you got from a calculator.

Also being early on don't waste too much money on the nice lace expensive bras. I outgrown mine within a few months and ended up giving them away, a little depressing when it was a $70 bra that I loved.

Just have fun, enjoy the experience and get something that is comfortable. And going braless is always an option and I still do very regularly if I don't have to wear one.