That's a good question. I'll be waiting to hear too

Once my 20 yo stepson moves out, his room is going to be my office/dog's bedroom

Any ideas how to get him out

?
For flooring, I'd do tile so it's easily cleaned/disinfected. Or linoleum, but a tough commercial grade, the regular stuff is SO flimsy.
I can't wait to see pics of what you end up doing, I'm so excited for you!!!!!