Pet Sitter - Full-time / Part-time

I have a situation going on and my dog is not getting enough exercise and to make it worse I'm loosing my fence for a yard. He's 100pound GShepherd, papered, chipped and shots. Not yet three and still a big excitable baby. He needs better training for the leash and just to burn energy. I have to work leaving him in a crate and that bothers me not being able to properly exercise him. If someone can at least discuss working with me I'd be very grateful.