-No clothes with any kind of potentially offensive slogans or images,
-wear covering clothes, normally includes belly and shoulders, but dependjng on your sixth form this might not be a rule (mine doesnt care too much)
-for bags there isn't normally any rule, I've seen people use tote bags, backpacks, plastic bags, Anything. I reccomend a backpack if you have one but you don't have to.
I hope this helps!