The gravitational force of a sphere (e.g. a star, planet, black hole) is not something that acts at a distance. Instead, it deforms spacetime such that other objects follow curved paths around it. Imagine a trampoline with a very heavy object in its center. If you place a ball on the trampoline, the trampoline dips around the heavy object and creates a curved path. The ball will then move along this path due to its inertia, "falling" toward the heavy object.
In the same way, the sun creates a curvature in spacetime, and the planets move along these paths, "falling" toward the sun. The gravity you experience on Earth is not because you're being pulled by the Earth toward its center, but because you're moving along a curved path through spacetime due to the curvature generated by the Earth.
The sun's gravity does not affect the sun itself, but rather determines how other objects move around it.
