You do not say what the degree is or where you were studying, but I would ask whether your school had any available career counseling. Even if you just graduated you might be able to access that help. In any field there are many different kinds of opportunities…. many different career paths a particular degree can open up to you.
Are you planning to work as a personal trainer? In fitness management or marketing? In health promotion.
Do you prefer to work in a hospital setting? A large club?
Do you want to be your own boss? Do you prefer to be part of a team?
Do you prefer working with a group, or with individuals?
With some paths you may want to explore working toward a second degree, such as physical therapy or nutrition or occupational therapy, for example, in addition to specialty certification.
With others having an exercise science degree is already something that will set you apart, and it is a question of which certification is best for what you want to do. And both Harris and Paul give great advice.
If you start by narrowing your list to ones that are NCCA accredited you will rule out a lot of inexpensive and often worthless options. I’ve worked in a few places that will accept many different certifications, but require them to be NCCA accredited.
Think about what you want to specialize in, look at places you would like to work and see what they are looking for, or require. You could go for a general personal trainer certification, and/or a cert. that targets clearly the specialty in which you wish to work. But whatever you get you need to balance getting the most prestigious one you can get for the money and time you have to spend.