Be bored.
I would drive to New York City and dance naked in Macy's front window.
Make plenty of beer and wine
Live in a beautiful log cabin atop a mountain overlooking a lake. Stock with beer and pizza and all the fixins' a 60 inch TV with remote control.
A cell phone just in case there's another only person on Blurtit.
You mean, after I got done wondering where the hell everybody went?
Go on an arson spree, and attempt to wipe out all evidence of other humans.
BURN, BABY, BURN!