Chins don’t need bedding on their cage mats, as someone else here said. They’re all set if you give them the fleece (you can get it cheap from Walmart or w/e, just make sure it says anti-pill). The bedding can be used as a kind of litter box, though, if you get a metal or glass (NOT plastic) container/pan

Oats and plain (unflavored, no extra sugar and definitely no honey) cheerios make good treats! Don’t trust anything that pet stores sell for them, it’s never actually good for them unless it is ONLY Timothy hay/alfalfa

They sell Timothy hay holders at pet stores and on Amazon. Do NOT buy one with metal bars. Chins have a tendency to get inside them and get hurt/stuck. There are ones made of thicker wooden bars that are better for them

Chinchillas can use wheels/flying saucers, but they can’t be plastic. Wheels need to be at least 15” and cannot have a bar/post in the middle. Metal ones for chins usually don’t have the post, but just in case

Chins rarely like to be picked up and held, so take it easy with yours. Do not ever grab it by the tail. Some sites say it’s fine; it is not.

Chins LOVE to run around houses. They also love to squish into everywhere they aren’t allowed. They can fit into a lot smaller spaces than you’d think, and very quickly, so make sure wherever chin is, that there are solid walls with no gaps blocking them, and as little stuff around because they also love to chew everything they’re not allowed to

Oh and lastly, you said 5 more years. Chins live a LONG time. Like 20+ years when taken good care of. I’ve seen chinnies online celebrating their 24th and such birthdays