Welcome!
I work too! And I leave our dog alone for those hours too (7:30-5:30) (since day one basically) So don't worry. It will be an adjustment. She will not like it in the beginning but the puppy will get used to it. (you may never, but they will eventually
) You've got the right idea. Just get an xpen. Put food and water on end, a pee pad on a another, some bedding with toys on another and your good to go.... Odds are in the beginning your puppy won't eat much when you are not home, so just make sure that when you are home that they do eat!
The beginning will be the hardest! So just stick with it!
Be consistent. It is no different than having a little baby
And we are all here to help!
Let us know how things go when you get the puppy!