Although, of course, it is impossible to disable gravitational forces, but this does not mean that we can not reason on purely this hypothetically. Gravity, it's such a thing that brings you back to earth during the jump. Well, thanks to her, an apple fell next to Newton. Imagine what would happen if she suddenly disappeared.
So, it's worth starting with the fact that our body is not ready for such changes. Even a brief stay at the space station carries a change. The muscle tone is lost and the bone mass is a known fact. In addition, the sense of balance changes, and the number of red blood cells decreases, because of which the wounds heal more slowly. If we add other facts, like those that make the spine longer, we can understand that in the absence of gravity our body would have evolved completely differently. For example, our muscles would simply atrophy, and people would never learn to walk.
But this is not at all the main problem that humanity will face. The Earth rotates at a high angular velocity, and imagine that someone is spinning our Earth on a huge rope, and then let go. Everything that was on earth will fly straight into space. Houses that are built reliably on the ground will remain standing, including, like the objects inside them (for a while), trees and plants too. But the seas, rivers, oceans will go to space the very first.
In any case, without gravity, sooner or later, the planet itself will collapse. Oh, yes, we all die, that's for sure.
Although this scenario, as we have said, is entirely hypothetical, it shows how important gravity plays in the universe. It is one of the four fundamental forces that govern the universe. The other three are equally important. Without electromagnetic, strong and weak interactions, the atoms themselves would fall apart.
But the gravitational force is the only one whose effect we feel from our own experience.