Pros
If you are getting this as a first job, it provides good opportunities to learn a variety of skills, including cash register skills, customer interaction, and customer satisfaction, among other things. If you are looking to move up into a manger position, they are always willing to give you a chance and train you for interviews, and I've heard once you are giving an MIT position, they are very helpful at training you, and the salary for managers is supposedly great. Also, they are usually pretty good with giving you the hours that you want, and working with your schedule.
Cons
I know people who work at a few different Wawa stores, so it is not just my opinion, but sometimes there is a lot of crazy things that you have to deal with, and not just customers. The managers sometimes take advantage of you, regardless of how long you've been there, when people call out repeatedly and they make you feel as if you HAVE to come in to cover shifts at times. They aren't always appreciative of your work.