Melanoma is the most common type of cancer in 12-24 year old Australians (Cancer Council). The MyUV website can tell you the UV level where you are and recommend the times you should take precautions. Your skin also ages prematurely when exposed to the sun unprotected.
Slip on protective clothing like a rashie or shirt
Slop on some sunscreen UV30+ or higher
Slap on a hat - preferably a wide brimmed one
Seek some shade
Slide on some sunnies.
My local beautician, You Skin and Beauty, offers Skincare and Makeup workshops for teenagers. They are not cheap but it is money well spent. You also get a goody bag to take home. Check beauticians in your area for similar workshops.
I just discovered this range of cosmetics. They are Australian owned and made, not tested on animals and are infused with superfoods. You can purchase them at selected chemists. So far I have only used their nail polish - which I loved. You can find their full range here. I think their kits are a great idea. At the moment they have a promotion where you receive a free Kabuki brush when you order two products online.