Kudos to you for taking initiative to stay safe in the sun. As much as we'd all like to admit that we don't enjoy having a tan, the truth is that most of us do feel better when we've gotten a little sun. And you can do that while being conscious of your skin's safety.
The FDA recommends that you apply no less than SPF 15, but this basic recommendation can be deceiving. Take a look at your skin tone, and your history with sunburn. Do you burn easily? Do you tan easily? Or are you somewhere in the middle?
For those people who rarely ever burn and get a nice tan in the summer, SPF 15 should be just fine. If you are very pale, have lots of freckles or have red hair, your SPF level should be much higher. (I am all of the above and never use less than SPF 50.) As an adult, you should know just how susceptible you are to the sun's rays and plan accordingly.
And if you take anything from this Q&A, remember to reapply no less than every 2 hours, sooner if you're in the water or sweating a lot. If you are going to start the day off safe, make sure you continue your day in the sun with reapplication. Don't forget areas that tend to be forgotten: ears, back of the neck, tops of the feet, and even your lips.
If you remember to apply the minimum SPF needed, you won't have to worry about being stark white this summer, and you'll know you are going to be safe as well. Enjoy the sun!