Would a human body float in the dense atmosphere of Venus?
No. According to the Nasa Venus fact sheet the density of the atmosphere at the surface is ~65 kg/m^3.

For comparison, water is 1000 kg/m^3. We only just float in water. 

So if you were there, in a suit that could somehow withstand the heat (464 C), the "air" would feel thick.

Maybe a person could strap on some wings and fly ...