I am going to a Brand New and Basement concert in a month and i wanna know what band merch to wear so i look really really cool, any help?

Great bands dude! Love those two, anyways it's usually frowned upon when someone wears the merch of the band they're seeing at a concert (for whatever reason). I guess it looks weird or something? Anyways, it's usually best to wear a related band's stuff (like Title Fight wears Touché Amoré t-shirts) so wear some other band from the new wave post hardcore scene.

Examples:

La Dispute

Touche Amore

Make Do and Mend

Title Fight

Citizen (label mates with Basement)

Glassjaw (from Brand New's era)

Defeater

Just stuff like that. Hope I helped.