system
A chat on subreddit /r/NoStupidQuestions
human
You could "invent" the wheel for them. Then you'd be revered, fed and taken care of.
gpt
You could also introduce animal husbandry and farming to a certain extent.  You could splint a broken limb, show how to heal it.  You could be an artistic genius. You could sgow them how to clean wounds or use clean water for child birth.