on the ground · on the floor

I sucked up the dust on the floor with a vacuum cleaner.

Your glasses fell on the floor.

I can place the palms of my hands on the floor without bending my knees.

Whales are said to have lived on land long ago.

You wake up lying on the rocky floor of a dark cave. A little light filters down from above. You can just make out a couple of openings leading away from the cave. What do you do now?