I'm not a fan of belly button piercing with "outies" or teenagers
Being a dad with two daughters of my own, both of whom wanted their belly buttons pierced as teen agers so badly they could taste it - they are now 23 and 20 years old, grown up and able to decide these things for themselves - I feel well qualified to answer your question. In addition to the fact that these types of procedures have very real risks that young people may not always consider, the fact that you have an "outie" is a real concern to me as well. Young people always want to be in fashion and do what everyone else is doing, and this makes it tough to listen to reason sometimes. I will commend you however for even being here and asking this question, because most people your age wouldn't show the maturity to put their ego aside and solicit expert opinions like this. They would rather sneak off and just do what they want to do! (Fortunately, my daughters didn't do that either!) In addition to potentially weakening the tissues around your belly button so that you may get increased scarring or stretch mark formation around your belly button with pregnancy or weight gain in the future, the fact that you have an "outie" means that you already have an intrinsic weakness of the tissues of the belly button. You may even have a small hernia in the belly button, and if this is the case, piercing through that could cause some injury or infection to the organs inside your tummy. Although these risks may seem small and insignificant, they are very real and not to be taken lightly. My advice is to be different than the majority of girls out there - get a new hairstyle or some beautiful earrings, and do the most important thing of all: be a warm, engaging, interesting girl, which will go so much farther in attracting others than any belly button piercing ever could. And leave the belly rings for other people.