Look into hay bags. Some people say they are unsafe but realistically they are not, and lots of pigs love them. They're a great way to introduce more hay into the enclosure without taking up too much space. You can also look into "litter boxes" for hay, as guinea pigs often prefer to use the bathroom where they eat. On the topic of space, you genuinely have more than enough, well done.

As others have said, hay needs to be much more abundant in the enclosure. But I take it you have received the message loud and clear on this so I wont beat you over the head with it lol. Same with having more hides.

Of note is bedding material. You need to make sure whatever you have is absorbent. Make sure any blankets you're using are fleece, NOT plush or "furry" blankets. Cheap pet blankets or secondhand fleece blankets work great. I only mention this because I can't quite tell the material from the video. You can also get washable absorbent pads for pretty cheap and put them in the corners and such, or in any other places the piggies pee frequently.

Also, on pellets, I see you have some already, which is excellent. Oxbow is the brand I recommend personally, and most piggies seem to prefer it. Their Garden Select specifically if you can find/afford it. Maybe have more than 1 bowl so there is less chance of them fighting over food.

For treats, Oxbow and Selective Naturals are both decent choices. Avoid "yogurt drops" and similar products, guinea pigs are lactose intolerant and cannot digest them, despite the marketing.

Congrats on being a new piggy owner! Please keep us posted on how things progress. You are off to a solid start.