This is a place name and it uses the kun'yomi. You haven't learned kun'yomi for 千 yet, so here's a mnemonic to help you remember it:
While you're admiring all of the leaves in Chiba, you realize you're craving something. What goes well with watching leaves? Why, cheese (ち) of course. Delicious Chiba cheese.
He’s from Chiba.
My mom loves peanuts made in Chiba.
It usually takes an hour and a half to two hours for a one way trip from here to Chiba.