I like your question. It shows that you are a good observer and curious about nature. And it isn't easy to see why clouds should be able to stay up when something as light as a feather can't.
A cloud is made out of jillions of tiny water droplets. Each droplet all by itself is too small for your eye to see. Each droplet is pulled toward the earth just like anything else. But tiny particles have lots more surface compared to their weight. That gives a lot of friction in moving through the air. Because of that they fall very slowly.
Even though they fall slowly, something else must work to keep cloud droplets from falling to the ground. What keeps them up there are upward-blowing drafts of air. If you have watched clouds, you have noticed that they are always changing shape. They are always moving in those gusty winds that hold them up there.
You can see that it takes a lot of different ideas to understand why clouds behave the way they do.