Parent/Child Communication, Inherited functions,

Hi, I'm pretty confident in C# but I'm only just getting used to Unity. I've googled around and I can't really find exactly what i'm looking for.

How do I have a parent object properly communicate with it's child. I know this can be done relatively simply using public classes, but i'm generally trying to avoid using public variables.

More specifically: I have a GameObject "WallOrigin" which instantiates a prefab "Wall". I do this because i'm trying to calculate the height of the wall, then stretch the wall accordingly. But I want the origin to stay in the same spot, hence WallOrigin.

WallOrigin has two scripts, one which creates Wall, the other Ray-casts to tp the ground to get the distance amongst other things. So I need to get the hit from the raycast and send it to the Wall which has a WallSizer script.

I know generally how this is supposed to work, but since they're separate objects i'd just like to know the best practice. If i just created the classes directly i'd just have them inherit the function. But I think i'm missing something with how getters/setters work here. Is avoiding public variables less important in Unity? Thanks

WallCreator:

 public GameObject wallPrefab = null;
     GameObject Wall;
 
     // Start is called before the first frame update
     void Start()
     {
         Wall = Instantiate(wallPrefab, transform.position, Quaternion.identity) as GameObject;
         Wall.transform.parent = transform;
     }

GetGround:

     RaycastHit hit = new RaycastHit();
 
     Vector3 oldPos;
     Vector3 floorPos;
     Collider floor;
     bool DrawLine;
 
     void OnEnable()
     {
         Debug.Log("On Enable");
         floor = GetComponent<Collider>();
         checkGround();
     }
     // Update is called once per frame
     void OnDrawGizmos()
     {
         // 
         if (oldPos != transform.position || floor.transform.position != floorPos)
         {
             hit = checkGround();
             //transform.GetChild(0).UpdateCube(transform.position.y - hit.point.y);
         }
 
         if(DrawLine)
         {
             Gizmos.color = Color.red;
             Gizmos.DrawLine(transform.position, hit.point);
             Gizmos.DrawLine(hit.point, hit.point + hit.normal);
         }
     }
 
     RaycastHit checkGround() 
     {
         oldPos = transform.position;
 
         if (Physics.Raycast(transform.position, -Vector3.up, out hit))
         {
             var distanceToGround = hit.distance;
             //Debug.Log(distanceToGround);
             if (hit.collider != floor)
             {
                 floor = hit.collider;
             } 
             DrawLine = true;
         }
         else
         {
             DrawLine = false;
         }
 
         //floorPos = floor.transform;
 
         return hit;
     }

WallSizer: using System.Collections; using System.Collections.Generic; using UnityEngine;

 public class WallSizer : MonoBehaviour
 {
 
     Vector3[] vertices = {
         new Vector3 (0, 0, 0),
         new Vector3 (1, 0, 0),
         new Vector3 (1, 1, 0),
         new Vector3 (0, 1, 0),
         new Vector3 (0, 1, 1),
         new Vector3 (1, 1, 1),
         new Vector3 (1, 0, 1),
         new Vector3 (0, 0, 1),
     };
 
     int[] triangles = {
         0, 2, 1, //face front
         0, 3, 2,
         2, 3, 4, //face top
         2, 4, 5,
         1, 2, 5, //face right
         1, 5, 6,
         0, 7, 4, //face left
         0, 4, 3,
         5, 4, 7, //face back
         5, 7, 6,
         0, 6, 7, //face bottom
         0, 1, 6
     };
 
     void OnEnable()
     {
         CreateCube();
     }
 
     void CreateCube() 
     {
         Mesh mesh = GetComponent<MeshFilter> ().mesh;
         mesh.Clear ();
         mesh.vertices = vertices;
         mesh.triangles = triangles;
         mesh.Optimize ();
         mesh.RecalculateNormals ();
     }
 
     void UpdateCube(float height)
     {
         Vector3[] vertices = {
             new Vector3 (0, -height, 0),
             new Vector3 (1, -height, 0),
             new Vector3 (1, 0, 0),
             new Vector3 (0, 0, 0),
             new Vector3 (0, 0, 1),
             new Vector3 (1, 0, 1),
             new Vector3 (1, -height, 1),
             new Vector3 (0, -height, 1),
         };
 
         CreateCube();
     }
 }