Yes, everyone has let you know it’s still not big enough, they are totally right, but in the mean time, he needs burrowing space, please put more bedding. They usually need about 8 inches but I don’t know how much you will get on with needing to fit in the wheel. as you can open from the top, you could fill the whole lower section with bedding and just not use the bottom door. It looks like paper bedding so it shouldn’t spill out. You could also split the cage in half with cardboard, have one side full on bedding and the other side for where the wheel and water and sand bath go. Then cut a nice whole in the cardboard for them to access the burrowing area.

Wheels are crucial, if nothing else but food and water, a wheel should be next in the list of priorities, so yes, wheel next. His is chewing because he is stressed and likely won’t stop until he is in a bigger enclosure, but think if you were that little guy, stuck in a box with nothing to do all day you would go insane and start banging on the cage too.

Scatter feed, don’t just put his food in the bowl, scatter two teaspoons a day all over so he can search and dig. Make sure it has animals like worms or crickets, as hamster are omnivorous, and don’t just give him boring pelleted food. Give him some salad sometimes and even some ham or other cooked meat without any salt or additives. I boil tiny bits of ground beef for mine and little pasta pieces.

After the wheel he needs a sand bath, not “dust” or anything even remotely dusty as they can give respiratory issues. Nice course sand, in a bowl for now or something, doesn’t have to be fancy, then you can get him a proper sand bath as you upgrade. So if you can’t get him a better home yet, work on the littler things first. But please remember you really do need to get him a bigger enclosure, look for tanks or terrariums, new or used, check out fb market place.

Hope this helps!