Proved is a verb.
Proven is an adjective.
You might find some wording out there that uses proven in a verb form—”I have proven the theory” (technically, proven is acceptable in past-participle form), but AP Style says it should be “I have proved the theory.” I say it’s wise to align with AP Style. It’s just safe that way, and you’ll always be correct if you use proved as a verb and proven as an adjective.
The child has proved he can behave well in school.
My friend proved she can run 13.1 miles.
It’s a proven fact that I love to edit.
She is a proven success in the sport of gymnastics.