Betta Fish: Is my betta healthy?

I got a betta just a few hours ago. Does he seem okay? His fin is a bit torn at the top and he has a small hole. And he looks droopy at the end, like curved. He was kept in a small plastic cup, so I'm guessing it's that. Hopefully he looks better soon.

One question, I have white sand and the shrimps I have are making a huge mess with their poop, is it possible to change the sand to black? Like just remove it. Honestly I don't mind it as much but it does look super ugly if there's a lot. I'm going to get more plants so hopefully that just covers it up and I won't have to think about it.

Referring to the pictures with the plants. Java fern, why is the top transparent and soft, why are the leafs like crumbling?Alternanthera reineckii mini, they don't look the best to me, will they fix up soon or… Peacock moss, when will it start really growing, because for now it hasn't changed at all. The bacopa momnieri is okay I think? I've had them for about a week. Is there something I'm doing wrong? Help.

What plants do you recommend I should get because it is quite empty in there. I'm really looking for something for the bottom because of the poop.. unless I can change the sand?

Thanks!