If you're a 粉丝 of Pokemon, 你 can create a gijinka.
Which means a "human" version of a certain pokemon. 你 have brown hair and eyes, 你 can pull of a brown outfit and be an Eevee so to speak. 你 can be as creative as 你 want. 你 can also add ears and a tail.
你 can look it up and see any ideas! :) Enjoy and have fun!
How long is your brown hair though? 哈哈 the easiest characters I can imagine to cosplay would be characters like in K-ON and similar shows. 你 don't necessarily need the uniform and can wear clothes from the EDs 或者 clothes they appear in outside of school in the show. 你 can get a black wig and easily be Mio with a purple hoodie, white short sleeve button down shirt, blue plaid skirt, and black knee tights. Ritsu wore a simple black hoodie, white shirt, yellow track shorts, and blue 斯潘德克斯弹性纤维, 氨纶 tights in the No, Thank 你 ED. In the new Singing! ED from the movie one of Mio's outfits is just a 粉, 粉色 dress and Mary-Jane shoes. The other outfits were a bit 更多 complex though but if 你 get two yellow hair things like Yui and a black hoodie with bear-like ears I'm sure people would figure it out without the rest of the clothing. (If they've seen the movie).
The brown eyes don't really make too much of a difference since people cosplay characters without having the matching eye color anyways. Hair dye isn't too expensive but make sure someone who knows what they're doing is putting it in 或者 be very careful. Wigs are fine too.
Here's Yui in the outfit I was talking about. 哈哈 her shoes are converse!