mold slugs mice in my accommodation

Hi, i’m going to be living in accommodation this academic year in September. I’ve gone to my house and it is covered in damp and mold. All of the rooms have damp in the walls and ceilings. Bedrooms, kitchen, bathroom & living room.

There are slugs in the house - in the kitchen and living room due to the damp. There’s also mice as someone has put down mice traps.
the floors are stained black and white skirting boards and walls have gone black with holes in them.

i’ve signed the tenancy for september for the year but what are my options here? Can i get out of the contract? is this legal to live here? is it liveable? who can i contact?