Or at least its harmful rays.
Spending the afternoon outdoors without sunscreen is asking for trouble now and way into the future. Burn marks are not attractive. Wrinkles--or worse yet, possibly skin cancer--will eventually be a problem if you don't protect your skin now. You will definitely need sunscreen so go ahead and get it now before you're spirited off on a picnic or a trip to the beach. Look for the SPF rating of at least 15 and also make sure it has UVA protection. Apply it half an hour before going out and reapply it after getting in the water or sweating.
Water -- you need it and an energy drink or soda pop won't do as well. Drink before you are thirsty. Keep hydrated, regardless, and pack enough to last the day and share.
Want to avoid sunstroke? Wear a hat. There are lots of them out there. Find one that's right for you before you need it.
Likewise, get some sunglasses. Whatever style you desire is fine, just make sure they protect from both UVA and UVB rays as well as at least 75% of visible light. There are standards for these things, but there are no government standards on sunglasses so you will need to be careful when buying. Look for "Z-80.3" to be printed on the frame to make sure you are getting a pair that meet the ANSI standards.
You will also need to protect your lips with a sunscreen especially for them that has at least 15 SPF. If you ignore this part of getting ready, you stand a chance of picking up really unlovely cold sores, also known as Herpes Simplex I.
The library has books on keeping your skin healthy and beautiful. Check them out!
Born Beautiful: The African American Teenager's Complete Beauty Guide by Alfred Fornay
Whether you're an all natural/just lip gloss girl or a full-on diva, this book can teach you how to appreciate and make the most of your own special beauty. Includes quizzes and color charts.
Recipes for Natural Beauty by Katie Spiers
You will probably be picking up a good sunscreen at the store, but these inexpensive, simple, natural, environmentally-friendly recipes can help you look your best when sun isn't a factor.
Skin: The Bare Facts by Lori Bergamotto
Tips for teens on cleansing, moisturizing, make up, and dealing with acne.