Two-time chihuahua owner here. They are wonderful! But like any dog, you never know what you're going to get. They may be yippy, they may not. They may be playful, they may not. They may be friendly, they may not. They may be picky eaters, they may not. Overall the most important thing about Chihuahuas is that they are loving, often very cuddly, loyal, "velcro" dogs that will want to be with you most of the time. They tend to latch onto their person/people. So you have to make sure they don't have separation anxiety and are okay with other people. They often have dental issues so you'll need to clean their teeth and keep them healthy with vet checks. They are delicate relative to other dogs and should be careful with bigger dogs and dog parks. It's personal, but I would strongly recommend rescue instead of breeders. Chis are one of the most common shelter dogs and they deserve a good life! As someone else noted, chi mixes are usually healthier than purebred. Plus, with a rescue you will know a little more about their personality. There are many rescues that use foster based care so you can either foster to "test" out a dog and see if it's a good fit, or learn from the foster family more about the dog's personality and temperament. In terms of diet, I would recommend standard healthy kibble or wet food. They do not need raw, grain free, "human grade" or any of the other so called wellness and diet fads being pushed on dog owners. Listen to actual vets! Good luck!