Come forward = volunteer for a task or to give evidence
The woman came forward with her husband’s finger prints.
Come from somewhere = originate in
The art of origami comes from Asia.
Come off = when something becomes separated or unstuck from another thing
The paint is starting to come off the wall in the kitchen.
Come out = appear or leave the inside of a place
It’s cloudy right now, but the sun should come out later
The phrasal verb come on has multiple uses, but when used as an exclamation, it can be encouragement for someone to do something, or it can mean something like “Stop being ridiculous!”
“I don’t want to dance. I’m no good at it; everyone will laugh at me.”
“Oh, come on! Nobody here cares whether or not you can dance.”