. Good answer.
I'm afraid I would take the whole situation deathly seriously if I found myself on the Enterprise-D with no crew. I'd arm myself while interrogating the computer about what's happened, determine if it's the 21st or 24th Century, and completely devote myself to finding a way to reunite the ship with her crew (and return her to her own time, if applicable). Of course, I'd be lying if I said my sudden undying devotion to reuniting the ship and crew was entirely selfless. There is a member of the Enterprise-D crew I would give literally anything to meet in reality.
And I would never return to 21st Century Earth, no matter what. That I can absolutely guarantee, even if I had to fly the Enterprise alone for the rest of my life with nothing but holograms for company.