I need help identifying this fish + help saving it’s tank

I have never had a pet fish before and know very little about caring for one. She’s a tiny thing but still moving around fine and eating, but she seems stressed. I put some photos of her tank and how shitty it is, I’m pretty sure some of what I’m seeing is mold :( For context I did not buy this fish. I am living at a sober living home currently and my manager who just got fired left her fish at the house. The new manager doesn’t have time to care for it so me and my roommate took it to our room. Any suggested advice is appreciated and we are wanting to clean her tank out as soon as possible and do whatever is needed. 🫶