Its something I want to do but I am really nervous! I know people will judge me for it and I am concerned about people I know seeing me. I have wanted to buy a bra and some undies for a long time. Should I just go and do it?
For yourself or for your girl? I'm personally against Victoria's Secret, but any proper lingerie shop will have an attendant to help you out. If you've ever seen the short-lived show Double Divas on Lifetime, that'll give you an idea. These women measure for a living and can usually guess size super accurately. I can't guarantee most shops will be as friendly as the women on the show, but they deal with a vast clientele. I would think people who work in lingerie are generally open and non-judgmental, so it's probably not as bad as you think.
People would just think you're buying it for your girlfriend. You can even act extra dumb and ask for help from the store attendants and claim its for your girlfriend might even make you feel more comfortable. You might need to take some measurements make sure you buy correct sizes.