As an 11 week old puppy he will need to go potty whenever he wakes up, after he eats, after he plays and everyone hour or so all day long. They need constant supervision to train and they cannot really control their bodily functions completely until 6 months so they can't always "hold it". They are like a human baby who must wear a diaper so don't expect too much until then.
With your school schedule the best you can do is keep him in an xpen, crate or playpen when you are gone with peepads covering the floor everywhere except where his bed and food and water are.
As for chewing the pee pads, they sell "frames" to put them in which makes it hard for them to chew them. I would try that. When you are home and can supervise him, you may want to tether him to your belt loop and watch him so you can take him to where you want him to go when he just wakes up, after he eats and after he plays.
Hope these tips help.?][ |