Well, if you know it’s T-friendly and are going with a friend or two I’d wear a cute skirt and blouse.
Jeans or leggings may be casual and somewhat feminine, but if you are confident enough then show it. Nothing beats a great pair of legs and a nice pair of heels. Just be sure that if you plan on dancing or standing around all night chatting that the heels are comfy or you will pay for your choice. There are “dancin’ heels” and there are “sittin’ heels”.
Go show them what you got and have a great time.