Advice needed :(

Hello everyone, this is stinky! i posted on here yesterday asking for advice on taking care of my new fish and getting him a proper tank set up (still a WIP don’t drag me through the dirt), but i noticed a few weird things, i don’t understand their behavior fully yet. He’ll swim around his tank and then hide but he’s been sitting oddly in the corner of it staring at a few bubbles then will swim around again. but i saw his fins and i don’t know if im just being paranoid but im unsure about the color of them or if they’re looking normal. can someone please tell me if im being paranoid because of the situation he was in or if i really need to treat him for anything? you can look at my profile for my previous post to see the conditions he was in to help give more context.