Pros
Depending on location, they will have clientele for you... Unless it's a slow salon then you'll be fighting for dogs and sitting around all day waiting for a same day apt. Also they are supposed to provide you blades/clippers/shears but most are garbage and you'll have to buy your own. The biggest PRO is that it's free training and a great place to start as a newbie with no money.
Cons
Dirty workplace, old buildings a lot of time, breaking/old equipment, too cheap to provide new stuff for salon only hand me downs a lot of time, cheap prices that are only worth it if you are forcing up selling packages, usually poor management (especially GSL's who take advantage of how they get paid,), NO HOLIDAYS OFF EVER, force you to work weekends and will put you on the schedule 7+10 days in a row during "blackout"(meaning no calling in/PTO during the holidays and everyone has to work MORE), strict policies that ruin efficiency and get in the way of your grooming, little control over your schedule with same day apts and you can't block your schedule to prevent this when you already have a packed schedule, and many more :)