How can I help my new cat adjust to living with my resident cat if the new cat is showing aggression towards the resident cat?

To help your new cat adjust to living with your resident cat, start by keeping them separated and gradually introduce them through scent swapping and supervised interactions. Provide separate resources like food, water, litter boxes, and resting areas to prevent competition. Use positive reinforcement and reward good behavior to encourage positive interactions between the cats. Seek advice from a veterinarian or animal behaviorist if the aggression persists.