Character costume design and research

We want our character to suit a look of a teenage boy that loves music, has a relaxed attitude towards life, and wears casual clothes to reflect that. We want to show this in his clothing.

I've drawn a picture of the image I have in my head of what Niall should look like. The clothing is casual, and looks like someone who acts that way, but is ready for anything. His attire looks like it would be an easy way to stay warm, but at the same time comfortable, and easy to travel in.
There's another image below, which is an example of the kind of shirt/hoodie I'm looking for.