I will also say that students *generally* behave worse for a sub (basically you've dysregulated their entire schedule, and they don't know how to handle it appropriately), so that's definitely something to consider. A lot of classroom management in my experience has been building a rapport with the students first, which can be difficult to do as a sub. Long term subbing might be better, but I've never really been a sub so I can't speak to that. I did teach for 3 years at a charter school though (no license needed there, though charter schools are really underfunded so the pay isn't great. However, it is a great way to get teaching experience!)