peter dresses kinda like I do. I have a jacket like that. I skateboarded with a passion for 3 years and even though my style has changed I still like close fitting jeans. But other than that he just wears skinny jeans, nikes, and a t-shirt. Depending on the wether he either has a zip hoodie on, or a zip hoodie and a brown jacket. It's pretty basic minus the pointless gloves, I really don't see where people have the big problem.
I mean it's not a matter of "what cool kids look like today" as SpiderMarvelite has been saying but its a matter of personality. This Peter looks more like an average kid which automatically makes him relatable, but he's very introverted and shy around people. Someone who doesn't have the best people skills and is ultra aware of it. He doesn't have confidence and he's generally quiet, someone who wouldn't really be accepted in the cutthroat high school environment.
Thats just my two cents, I think it works.