New Dog

My fiance and I got a new dog. The dog was her mother's, the only problem was that her mother's 4 other dogs were beating him up. He's cute, he's skittish, and he's the devil. Jack peed on me last night!! The little rat, I was gonna toss him across the backyard. I didn't but I wanted to. He isn't fixed....yet, so he marks everything. help!!!!!!!!!!!!!!!!!