The centripetal force is the force acting on the object which is in uniform circular motion and the gravitational force is acts due to acceleration due to gravity of earth.
The centripetal force always acts towards the center of earth when object moves in the circular motion.
Consider the motion of earth around the sun, it is normally known as uniform circular motion. The centripetal force acting on the sun is due to gravitational force between the earth and sun. So, they are balanced in this case to keep the earth in a uniform circular motion around the sun.