A pro would be that the company can't rip you off with your pay. If it's a very large well known company, everything will be done legally. I once worked in a small shop and they totally ripped me off $400 and I couldn't do anything about it.
A con would be that all of your friends would know you worked there, everyday you would see somebody you know. Personally that doesn't bother me, but some people don't like people knowing where they work etc.
I worked at one for a little over two years in high school. Pros: It's a job, work experience, socializing, a chance to learn some skills, and there's usually high turnover which means you'll have more accountability and responsibility quickly even if the pay doesn't increase for it. Cons are low pay, hours can be less than desirable (I started out working 4 hours a week, sometimes on Sunday one week and Saturday the next, so 13 days later. After a year and a half I was being scheduled for 5 days and 30 hours while trying to go to school and not work 8 hours every Sat and Sun). Also little chance of being promoted/advancement, a lot of corporate-mandated programs/rules/training that doesn't necessarily fit for your store, and lastly the jobs can often be pretty boring.Can a 14-year-old work in a clothing store?