Traveling between spherical planets

I have been trying to figure out a solution to space travel for the past week, and my brain cant take it anymore. I am here to ask you guys to help. So i want to make it so i can travel between planets. Using the scripts below(Unless you have anybetter scripts for what I am trying to accomplish). I want to make it so the gravity body/player and enemy's go to the closest planet that has the tag "Planet" and i have read the manual on Tags, and saw the "ClosestEnemyTag" example but i just could not figure out how to implement it into the script. Whoever helps me with this is a savior, and I thank you so much.

 using UnityEngine;
     using System.Collections;
     
     [RequireComponent(typeof(Rigidbody))]
     public class GravityBody : MonoBehaviour
     {
     
         GravityAttractor planet;
         Rigidbody rigidbody;
     
         void Awake()
         {
            planet = GameObject.FindGameObjectWithTag("Planet").GetComponent<GravityAttractor>();
            rigidbody = GetComponent<Rigidbody>();
     
             // Disable rigidbody gravity and rotation as this is simulated in GravityAttractor script
             rigidbody.useGravity = false;
             rigidbody.constraints = RigidbodyConstraints.FreezeRotation;
         }
     
     
         void FixedUpdate()
         {
     
             // Allow this body to be influenced by planet's gravity
             planet.Attract(rigidbody);
         }
     
     
     
     }

 using UnityEngine;
 using System.Collections.Generic;
 using System.Collections;
 
 public class GravityAttractor : MonoBehaviour {
     private GameObject player;
 
     public float gravity = -10f;
 
     
     private void Update()
     {
         
     }
 
     public void Attract(Rigidbody body)
     {
         Vector3 gravityUp = (body.position - transform.position).normalized;
         Vector3 localUp = body.transform.up;
         
         // Apply downwards gravity to body
         body.AddForce(gravityUp * gravity);
         // Allign bodies up axis with the centre of planet
         body.rotation = Quaternion.FromToRotation(localUp,gravityUp) * body.rotation;
     }  
 }