I’d hold off until you actually feel comfortable handling a dog. You can volunteer at shelters or babysit a friend’s dog or something, but you’ll need to train your dog, and being afraid will make that a lot harder.

Training a dog is one part training yourself. Your dog will look to you for guidance, so it’s helpful for a professional trainer to show you how to communicate with your dog. There are private trainers, but the most affordable method is in a group with various other untrained dogs.