Black Holes. Where are they located in the universe? Path of movement?

Every galaxy has a supermive black hole in the center. The black hole I want to say is randomly spread. To create a black hole a mive star must implode. They are random, but there is a process into becoming a black hole. there is actually a star orbiting a black hole. And that can be explained by the fact that most stars are binaries, one star supernovaed and formed a black hole and the other one did not die.