Hey guys, Total rookie here, but I need to make a couple repairs before I move out of this place and don't have any friends IRL who can help with this sort of thing. Here's a crack I put in the surface of the wall when a kitchen cart fell into the corner. I don't know the name of the material, but as you can see it's a white plastery uneven material with a medium gloss. Beneath that is some kind of metal corner that I hope I need to completely obscure, especially because it's bent up quite a bit. Forgive my ignorance and feel free to correct me, and I'm sure I can get this done with some clear instructions!