Nervous dogs are bad. A secure dog will be relaxed, calm, friendly and easygoing in almost all circumstances. An anxious dog will be snappy, growly, shaking, hiding, and will possibly bite, and that can happen in nearly any circumstance. You're at home with your dog and a friend comes over, your dog tries to bite. Bad stuff. Certain breeds are just anxious by nature, and Akitas are one of them.
Smart, high energy dogs are bad. An experienced dog owner will know how much time investment is involved and what the best ways are to keep the dog happy and occupied. A bored working dog, like a border collie, becomes destructive. They'll chew your furniture, your toys, go potty in the house, become moody and withdrawn or develop other behavior problems. First time dog owners should go with a breed that fits their current lifestyle.
Breeds with serious health problems or needs are bad. You don't want to get a sharpei as a first dog if you aren't prepared to clean out the wrinkles to prevent infections or smells. You don't want to get a french bulldog if you want a running buddy because the poor dog's nasal passages are barely suited to getting enough air to walk.
Breeds that are very protective are bad. A sharpei is a one-family dog, will love you and guard you to the ends of the earth... including against your mother in law, neighbor's toddler, or other innocuous person in your life. If you don't have the expertise to teach the dog that people are generally good and safe, you will have a poor experience.
Somebody above mentioned golden retreivers; that is a great first time dog. Friendly with everyone, up for anything you want to do but not hyperactive, and requires a medium amount of care for coat and health.