I took a friends betta fish that they no longer had room for so please don’t judge and I appreciate all helpful comments. I’ve had him for about a week and when I got him his fins were already a bit torn I think it was due to the decorations they had but I also want to make sure it’s not fin rot. Also his left gill is sticking out slightly and I don’t know if that’s a problem. He is in a 10 gallon tank, very active and is eating good. I’ve attached some pictures.