I know of a Youtube beauty personality who's very popular among young women and teens and pushes a lot of expensive anti-aging products, claiming they will "prevent" wrinkles. They won't. The tendency to get wrinkles is a combination of genetics and lifestyle. For anyone under 20, putting a lot of thick anti-aging products on your face will likely only make it break out. You will literally be washing your money down the drain.
Many anti-aging products target two things: skin cell turnover and collagen production. Products like retinol and alpha hydroxy work by stimulating these in the skin. When you're in your teens and 20s, your skin is naturally very efficient at both cellular turnover and collagen production. Adding a product to artificially boost this process won't preemptively stop the natural aging process from occurring.
The biggest thing I emphasize for any teenager is broad spectrum sunscreen (a chemical blocker) or sublock (a physical blocker). Look for UVA and UVB protection on the front and wear at least SPF 15 on your face and neck year-round. Salicylic acid products, which are associated as an acne fighter, have the added benefit of exfoliation.
Once April comes, I recommend increasing the the protection to SPF 30. Especially in the summer when you're at the beach, be diligent about sun protection: These are the years when most of the sun damage you'll see as an adult accumulates. SPF lasts about three hours, so make sure to reapply. Also, hit the areas people tend to forget: Ears, tops of feet, and hands (make sure to wear a lip product with high SPF). Even if you have dark skin and don't tend to burn, wear sun protection. You are equally susceptible to skin damage; it's just less visible immediately.
If you're young and have dry skin, invest in a moisturizer you like. You don't need to spend more than $15 for a product, and applying more of it won't make it work better.
This is the age when you can get away with spending very little on skincare. The one thing this Youtube personality says that I agree with is, "Prevention is key." I just think that prevention should include not spending $50 on a high-end anti-wrinkle cream.