How can I decorate on a mug or plate with paper? I remember when I was in school and the teacher gave us just newspaper. We cut words from it and decorated our mug or plate. I don't remember how we glued or adhered to the plate or mug so it was permanent.
Do  you know a way how to fix pieces of (news)paper to a white mug or plate, so it is

permanent
non-toxic
food-safe

It does not have to be newspaper specifically, any common household paper (or alternative materials) should work for this.
You can use mod podge (decoupage glue) to decoupage your paper designs onto the mugs and plates - there are many tutorials for decoupage all over the he internet.
Once your decoupaged mugs / plates are completely dry and cured (leave it for a few days to be sure) you can apply several thin coats of a water based polyurethane varnish (leaving plenty of time for each layer to dry) to seal it and make it food and dishwasher safe.