If it works exactly like a ball that is placed on top of a cloth, doesn’t the celestial bodies that is rotating around the ball will eventually get sucked into the center?
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The ball-and-cloth analogy is a bit misleading since, in that analogy, the ball is making a dent in the cloth because it is pushing down on it due to gravity. But the analogy is supposed to explain how gravity works in the first place, so it ends up being circular (and so the short answer to your question is: it does not work exactly like that).
The point the analogy tries to convey is that gravity, in Einstein’s theory of General Relativity, can be understood as “bending spacetime”. So what does that mean? Well, recall Newton’s first law: objects move in a straight line unless a force acts upon them. In classical mechanics, we understand gravity as exerting such a force, and this explains e.g. why planets orbit stars: the star exerts a force on the planets that causes them to follow a curved trajectory rather than a straight one. In Einstein’s view, gravity is instead better understood as locally changing the definition of “straight”. So, planets orbiting a star don’t experience any force, and they keep moving in a straight line, but that line is warped by gravity so that it goes around in a circle around the star.
(If it helps, think of taking a piece of graphing paper and rolling it up into a cylinder so that the ends of the graphing grid meet. Now imagine an ant walking along the grid lines (it helps if you also think about the ant as being two-dimensional). From the ant’s perspective, the lines seem to be straight. And yet, if it follows one of the lines that wraps around the cylinder, then it ends up back where it stared.)
If that (i.e. a force vs. bending of spacetime) seems like splitting hairs or arguing semantics, that’s because this different way of thinking doesn’t really make a difference for many day-to-day situations or basic physics problems, and so often Newton’s theories work just as well and are easier to understand intuitively. But Newton’s theory of gravity can’t explain why, for instance, light is affected by gravity, seeing as light consists of photons and photons have no mass. In Newton’s theory of gravity, you gotta have mass in order to experience gravitational forces – it says so right in his formulas. In Einstein’s theory, you don’t, because spacetime around you is warped and you are moving in spacetime, and therefore a straight line becomes a curved one whether you have mass or not.
As for your final question: again the analogy breaks down here and for the same reason that I said at the start, as it is trying to explain gravity with an analogy that itself invokes gravity, which messes with your intuition for how things will play out. Just think of the orbiting object as following a straight line that happens to go in a circle around the mass it orbits. In an idealized situation, this means the object will stay in orbit forever. In practice, there are various mechanisms that cause [orbital decay](https://en.wikipedia.org/wiki/Orbital_decay), and so eventually orbiting objects will fall towards the mass they orbit.
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