Your boxer looks almost identical to mine.
I've had one for 5 years now. Great dogs imo. Mine is about as loving as you can get, always has to be near us when we are home. Absolutely great with kids. They are pretty hyper and playful all the time so it's best to learn to calm them down when you want to. It's best to walk them every day or to have a large back yard so they can run around in. Like most puppies they will tear **** up if left alone.
Health wise like most larger dogs they can have hip problems so keep an eye on how your dog runs around and walks to see if any signs of limping happens. They also are bad to have skin problems (lumps mostly) so keep an eye on there skin.
O yea, get him/her a bone to chew on. Mine chewed on a rock outside without me knowing and broke off one of his canines.
Below is a link to the Boxer thread here on PBN.