Why is everything in the universe round

all natural things are round like planets, fruits, vegetables, and some animals.

so space-сum can distribute itself evenly over it

Mainly due to gravity, it's a law of the universe, gravitational laws for example. This forces most large objects to become spherical. It is because forces act radially, in other words if you take a point in space everything tends to radiate in all three dimensions equally and the fading happens in a similarly even way.

as for animals and plants it is more to do with the surface area to volume ratio, nature is lazy and hence it tries to get as much stuff inside an object using the least amount of surface to waste. A sphere is as close as you can get to that.

Planets are round because gravity forces it to be round by pushing it from all directions, as for fruits, maybe because the fruits grow outwards in all directions, natural things usually don't have points or edges because there would be no point in it (pun intended)

Because it is the perfect shape to uniform growth when there is no outside force acting against it. To make a shape other than a round object there would have to be some intelligence or force at work. The only exception i know of is crystalline structures.

You have struck upon something fundamental about our universe. Another fundamental is circular and simple harmonic motion...these are keys to help unlock the mysteries of the universe. Stay tuned.

everything is NOT round

look up "fractal" geometry and the Mandelbrot set, it is beautiful

Planets are round due to gravity, as for fruit and animals I'm not sure.