Communicate with your landlord. If there is a problem, let them know. For some things, including requested repairs, it’s a good idea to put your requests in writing and keep documentation of your communications.
Get renter’s insurance. Not only does this protect your property within the house, it may also cover damages to the property for which you and your roommates are “joint and severally liable.”
Document your complaints and requests for repair.
Always get permission in writing for pets and new roommates.