Bethany,
It really depends on your skin tone. I always use a 30 spf to start and then maybe go down to a 15 (always use 30 on my face). I come home with a great tan everytime and don't burn. I did get burned on one trip and have been very careful ever since. I had to stay inside for 2 days...not fun while you're in Aruba!!
Have a great honeymoon, I am sure you will want to return year after year!!!
Lynda