How do I stop being scared of dogs ?

Im 16 years old. I found a job at a groomers. I want to work there but i'm scared of dogs. The groomers also has dogs that he watches there . So i have to walk them. They are German Shepard's and many other dogs. I really want this job to work and i don't want to be scared of dogs. My best friend has a boxer so i never go to her house cause i am scared of her dog. My brother says that the German Shepard just gave birth so she is not wild. I dont know what to do. Please give me advice . thank you.