Nice to meet you Shelby. Welcome to you & Rudy. Thank you so much for choosing to rescue.
My advice is that you crate Rudy when you leave the house. Its good for him to become accustomed to the realty that he will be left alone and his crate is his safe place. And for the second challenge, always go outside with him.
Mac - 3.5 year old GSD
Bart - 6 year old GSD/Akita
& 3 Cats Buffy, Rusty & Magoo