Burn down some cities, play with some aircraft and toys that would normally be out or reach. Wander through like a kid in a candy shop through most of the world's museums. Most likley continually half drunk on some 500 year old Ports
It would be a completley selfish playtime. Since there would be no reason for future progress or any legitimate merit in my actions, it would be a very hollow life if not for personal desires.
But without limits and without consequence and no one to share them with or do them for. It would get boring quickly. I would play until I was bored, then just kill myself. Say in about 6 months or so.
Dark, but honest.