does the sun have an orbit? And if so, does this point also move around somewhere? where does it stop then?

Answer

The sun is one of approximately one hundred billion stars in the galaxy, and its orbit is therefore also determined by the global gravitational field that these hundred billion stars together generate. The lstars in the galaxy rotate slowly around the center of the galaxy. Rather, the sun is on the outside of the galaxy’s disk and takes 250 million years to complete one rotation. She does this (and with her the entire solar system) at a speed of about 220 km/s. Stars further outward take even longer to complete one revolution around the center of the galaxy.
The galaxy, in turn, is part of the Local Group, which also includes the Andromeda Galaxy (M31) and a host of smaller companion galaxies. Here, too, gravity is the determining factor for the mutual movements. The gravitational center of gravity lies somewhere between our galaxy and M31.
(for more info about the local group : see : http://en.wikipedia.org/wiki/Local_Group)
On an even larger scale we come to the “clusters”, collections of hundreds of galaxies, and the even larger superclusters. Our local group is part of the Virgo Supercluster. The largest structure in the universe are the filaments. The universe also contains gigantic areas in which no galaxy or clusters occur. This is called “voids”. The fimalents are the boundaries of those voids. see : http://en.wikipedia.org/wiki/Large-scale_structure_of_the_cosmos

However, space has no point around which everything revolves. So there is no center in the universe. Just as there is no center on the earthsurface is. Any country in the world can call itself the center of the world, but no country has more reason than another to do so. In the same way, but in one dimension more, every point in the universe is the center, or rather, no point is the center.