It’s important to bond with your rat if you hope to handle it, train it and play with it.
A good way to bond with your rat is to spend time with it. Sit near the cage while your rat is eating and talk to it. After your rat has at least a week to adjust to its new home, start opening the cage door and calling it to you with a treat in your hand. Your rat will quickly learn to come to you and take the treat.
Next, let your rat out of the cage to roam in a rat-proofed room and hang out with it. Offer treats from your hand. Once your rat comes to you regularly, begin picking it up and putting your small pet in your outstretched hand. Offer treats while your rat is there so it associates being held with something tasty.