For an outfit that's super simple but can be modified in a variety of different ways, opt for a tan raincoat and a crew-neck sweater. Introduce black leather derby shoes to the equation for a touch of elegance. If you want people to see maturity in you as a teenager, an ensemble like this is a fail-safe option.
Who said you can't make a fashionable statement with a casual outfit? You can do that easily in a tan raincoat and a crew-neck sweater. If you want to break out of the mold a little, introduce a pair of dark brown suede derby shoes to the equation. As you're maturing from a kid to a teenage guy, you probably want to start dressing more like an adult. If that's the case, combos like this are ideal as inspiration.