I was assaulted( I think) and I don’t know what to do...

I’m a 12 year old female, and I’m about to turn 13. Today in school during dismissal ( I go to a catholic school so no matter how old or young you are we line up) on line I was in the back. My friends be hind me we’re back talking and someone comes up to me and slaps my butt. And I turn around and my teacher was right there, he smiled at me, then went to the front of the line. One of my friends saw it and he said that the teacher did touch me, I just don’t know if it was an accident or something malice. I’m going to talk to one or two of my close friends in school tomorrow to get input from people who know me and him.

Also last year one of my best friends( all my friends at guys) used to touch me on the bus. He would rub my thighs and sit really close to me and pop a boner every now and then. Then he started jerking off? On the bus. He would mess with his penis and stare at me. This year he didn’t touch me but he shows me porn on the bus some times and it makes me uncomfortable. Please help me. This is all from today so please comment as soon as possible so if I decide to I can report him so it doesn’t happen to another student.