Here are the steps you need to take.
1. Do some research and decide what kind of dog you want, using
DogBreedInfo or
SelectSmart.
2. Google the dog breed you choose with your location. Or, you can go through the
AKC, they have a list of breeders in the area where you are. That should get you some kennels in your area, and you can view their websites and check out the dogs they offer. All reputable kennels will offer references. CHECK THEM!
3. Speak with the kennel owner and make arrangements to purchase your dog. A REPUTABLE breeder won't let the puppy come to you until it is at
least 8 weeks old, preferably 12. That gives the puppy time to socialize with its littermates and be completely weaned before you get it.
4. Before you get your dog, you should have a space in your home that is dedicated to the dog. Even if you are crate training your dog, the crate needs a particular place where it
always is. I would also take the time to puppy proof your house... Make sure all the cords in your house are inaccessible, clean up so that there are no shoes and other things you don't want it to chew up. Buy the dog some toys... Puppies teethe just like babies do, so you'll need some nice chew toys that they can gnaw on.
5. Make arrangements to take some time off work/school for at least the first one to two weeks after you get your dog, so that you can potty and crate train the dog.
6. Pick up your puppy.
You are going to have to work up a schedule of feeding and potty times... Your puppy should be taken to go potty 15 minutes after they eat, and if they don't go potty then, you'll have to take it out every 10 minutes or so afterwards until it does go. And you'll have to take it outside to potty about every 3 - 4 hours, returning outside every 10 minutes or so until they go potty. Decide on a Key word. I use 'go potty' for mine. When they do their business, say it while they go, and praise it.
To crate train, you'll have to BE THERE to do this, just like potty training. Open the crate and line it with an old blanket or pillow. Place the puppy in the crate and close the gate. Stay where the puppy can see you, then let it out in about 15 minutes. Praise it, then play with it for a while. Put it back in the crate for about 15 minutes again. You'll have to do this in increasing times for several days. Don't give in to the whining and barking.... DON'T yell at it. You'll have to get the puppy accustomed to the crate, make it feel like the crate is its special place. Again, a special word that refers to it is good. I use "bed" for mine.
I still don't think you've thought this through. You keep repeating that the dog has to be home by itself for 5 - 6 hours a day.... This isn't a huge deal,
AFTER the initial training time. I took two weeks off work when I got my female, and she was almost 3 years old, NOT a puppy. I took almost a month off the last time I had to train a puppy. Even after I went back to work, I was home every day at lunch, and I didn't leave the puppy alone for more than 4 hours at a time for another month, at which time he was fully trained. And unless you are planning on having a house, a boxer is not going to be the most likely breed for you.... They are fairly large, require quite a bit of care, and it is incredibly important that they be exceptionally well-trained before you ever leave them alone. They can be VERY destructive if you don't, and they do NOT like to be left alone. I have a boxer/pitbull mix who dug up the floor of the home I rescued her from. The previous owners didn't bother to train her or teach her anything, and left her alone for hours at a time.