Pets can be purchased with money or gold.
Head to your nearest animal shelter to purchase your pet.
Buy pet using gold
Buy pet using money
Cycle through pet colours
To summon and interact with your pets, you can access the menu by typing /pets or pressing F6 then pets. All pets can be picked up, some will go in your arms, others will go on your shoulder, however only some pets can learn tricks, one being dogs of course.
To teach your pets drinks, they need to gain experience. Pets gain experience by walking, running, sprinting, eating, drinking. If they have a trick available they will also gain experience when you tell them to do that trick. Once a trick is available you do have to ‘teach’ it to your pet. As your pet levels up, more tricks will become available to teach them.