1). Of everything that makes up the entire solar system ... the Sun, eight major planets, more than a hundred moons, bunches of dwarf planets, all of the asteroids, huge quantities of asteroids, comets, and meteoroids, millions of Kuiper Belt objects, millions of Oort Cloud objects ... if you add up the mass of EVERYthing, the Sun has more than 99% of all the mass, and everything else has less than 1% of it.
2). The gravitational force between the Sun and each object in the solar system keeps the object in orbit around the sun.
-- Also, the gravitational force between a planet and each of its moons keeps that moon in orbit around that planet.
-- Also, the gravitational force between the Earth and the ISS, and between the Earth and every TV satellite or weather satellite, keeps each of those objects in orbit around the Earth.
