Pros
You get to pick the days you work half days full days. If you like a school, you can ask them if they need you long-term and then stay at a school longer. If you find a good school, I suggest you stay as long as you can.
Cons
Very low pay, you will have bad behaviors, not only in students, but also teachers/staff. And I’m told the schools have every right to change your job last minute So you can go to school thinking you’re gonna be a substitute for a class and next thing you know you’re wiping tables in the cafeteria all day. You will have inspections twice a year unannounced and they will watch you interact with the kids teach and tell you everything that you need to work on. (which isn’t bad but the times that I’ve had it they interrupt the class and try to take my attention away to talk to me which can be distracting in a classroom full of six-year-old )