Reddit mentions of Pink Floyd Boys' Big Short Sleeve T-Shirt, Black, M-10/12

Hey, I feel you on the nervousness, but yay, that's really exciting you are going to your first Pride!! :)

I would also second miminari on mostly focusing on wearing what you are comfortable in! Facepaint is wonderful for drawing on easily removable rainbows and designs, you could hold a rainbow flag/wrap yourself in a rainbow at the event if one of your friends wants it afterward and you don't want to bring it home with you, you could get a bracelet or make your own with rainbow beads or braided string, there are also some clothes that have patterns with rainbow colors but aren't as flashy as having a rainbow flag on them (seriously! search rainbow shirt or skirt or dress on Amazon, and you can get things like this or maybe this or even this if you want to say somebody gifted you a shirt and there are many other examples if you do some digging!), and/or you could see if your friends would chip in and you guys could make your own t-shirts with tie-dye or just fabric pens to draw on rainbows and things

I hope this helps somewhat and that you have an amazing time!!