Hair thinning??

I picked up a cat/kitten earlier today. It looks healthy and is super playful, but it seems to have thinning hair above its eyes to ears. Online I saw that it is normal in aging cats, but he is quite young. What can it be? It does not have sores/scratches etc. he's just shedding a lot. Picture attached.

Congratulations on your new kitty!!  He looks like a sweetie.  The thinning hair in that area is totally normal and happens as a cat transitions from kittenhood to adulthood.  The shedding is probably a combination of less than ideal food and stress.  Cats tend to shed when they're stressed.  Be sure to get him on a high quality canned food supplemented with dry and he'll be fine.  You'll also want to get him to the vet sometime this week for a wellness check and get established with the vet.

Thank you for your quick response. We will try to get him to the vet today. Do you know when they start spraying?

If they get neutered early, they shouldn't spray, but this isn't a guarantee.  He may never spray.  I have a male cat that we've had since he was about 10 wks old.  He's never sprayed since he's never had to define his territory.  So, if he's not neutered, get him neutered immediately.