i got my boxer puppy at 8 weeks. she was used to being with her parents and brother so we made provisions for that. not sure if mentioned, but we made sure that she had a large stuffed animal to cuddle up next to in her kennel, and underneath we put a ticking clock to mimic the rhythym of a heartbeat. her kennel was next to our bed so she could see us. she whined for two nights and then that was it.expect whining. its what they do. if you can't handle it, then a puppy isn't for you.
in terms of potty training, her meals were scheduled, no free eating. that way we could make sure she went outside right after. we would take turns letting her out at night, because puppies can't hold their waste in for a long time, and will generally not eliminate where they sleep. she was praised for getting it right, and her word association is still, "potty outside." DO NOT engage in punishment conditioning for potty training, i.e. yelling or hitting when they don't get it right. we just didn't comment on it.
RESEARCH. RESEARCH. RESEARCH. its very helpful so you know what to expect. I visited boxer forums, dog behavior websites, got dog books from the library, etc. A dog is an amazing companion, but you owe it to them to think on their level when raising them, so they become well-adjusted. logic has no place in a dog's life, association does. exercise is everything, its not fair to keep them locked up for hours at a time, so I don't recommend them for single people with jobs. good luck!