1. Go to the Pet Store: You can browse through the list of available pets and choose one that you like. Once you've found one, you can click on the "Buy Now" button. You will then be prompted to confirm your purchase. After you've confirmed, your pet will be delivered to your dorm.
2. Adopt a pet: If you don't have enough credits to buy a pet from the Pet Store, you can try adopting one. There are a number of Habbos who give up their pets for adoption. You can find these pets by going to the "Adoption Center". Click on the pet that you're interested in and then click on the "Adopt" button. You will then be prompted to confirm your adoption. After you've confirmed, your pet will be delivered to your dorm.