Many factors involved in cloud formation, variables and what keeps them aloft until rain drops form within them then fall to the earth.
Factors include Air pressure, air temperatures, humidity levels, condensing of humidity, air flow, solar radiation, land or surface temperatures, changing temperatures from surface to top of cloud formation and more.
Clouds in no way disprove gravity, nor do they completely disprove "Universal Acceleration" in FET, at least not with the model with a sealed dome over the earth. But that a subject for another discussion.
Air flow alone has a huge effect on many objects. When you look at how little of air flow can keep a feather or piece of paper aloft you get some perspective.
Try tearing up several sheets of paper, point a small fan upward set on low, then release the paper in front of the fan and note how they easily float upward. Turn the fa off and they fall to the earth.
Fill a balloon with hot are and it rises, blow at it and it will move the direction you blow even upward.
There is always humidity in the air even on a hot summer day. You can only see this humidity when it condenses enough that light reflects off it. Only when the humidity condenses enough to become liquid droplets large and heavy enough that the other factors have little effect on them do the succumb to the forces of gravity.
For an example of varying temperature layers from ground to clouds is 'Ice Rain'.
This phenomena occurs when the humidity condenses into droplets in the clouds where the temps are above freezing at that altitude, begins to descend, passes through a layer of air that's below freezing forming frozen cylinder shaped ice pellets that hit the ground in that form even when the ground temps are above freezing. I see this a lot in the mountains where I live.
Also I have experienced being in the clouds where you can see multiple levels of condensed water vapor simultaneously in the form of fog, wet fog and even small water droplets that hang in the air and get you soaking wet without fall in the form off rain. Just walking through it or the win blowing it on you.
Even snow flakes you can watch the wind blow them all direction but when the wind stops they fall to the ground.