I'd wear a red tank top, black long baggy pants/black skirt and red Jordans or just black/red shoes in general with a black bow/headband and silver jewelry
but that's based on me obviously wear whatever looks good for your body type and comfortable
(you can prob tell Iv been to alot of concerts) \

Well, I'm not too sure about your taste in dressing and stuff but... I do have some tips!! You should probably do a little bit of research about the place you're going to the concert, for example, if it's indoors or outdoors, what's the weather like, the estimated temrature, etc.
And depending on that you should be able to get the right clothes to suit the surrounding environment and be comfortable in them!! You should also wear clothes that are both comfortable yet stylish cause ykyk, you wanna look good, feel good, and remember this time to be good!! But if that's not enough, you could also look for concert outfit ideas on Pinterest!!

Not the most helpful of thoughts but id prob just throw on a hoodie and call it a day
I havent rly gone to any concerts before either