How to add something to a list on awake

Hey how do i make my building add itself onto a list there is on another gameobject i just cant seem to find out how. this is my building script where it should add itself on awake

public List<GameObject> buildings;

    void Awake()
    {
        instance = this;
        buildings = new List<GameObject>(GameObject.FindGameObjectsWithTag("ListGameObject"));
        buildings.Add(gameObject);
    } 

and this is the lists script it needs to add itself onto

    //Lists
    public List<GameObject> buildings;
    
    public void Update()
    {

        //Building List
        buildings = new List<GameObject>()
        {

        };

    }

Try this approach. Create something like a manager class which holds the list of buildings in game.

Manager Class

public class BuildingManager : MonoBehaviour{

	private List<GameObject> _allBuildings = new List<GameObject>();
	
	public static BuildingManager Current;
	
	private void Awake(){
	
		if(Current == null)
			Current = this;
	}
	
	public void AddBuilding(GameObject building){
		if(!_allBuildings.Contains(building))
			_allBuildings.Add(building);	
	}
	
	public void RemoveBuilding(GameObject building){
		if(_allBuildings.Contains(building))
			_allBuildings.Remove(building);	
	}
}

Sample Building Class which adds itself would look like this.

Building Class

public class Building : MonoBehaviour{
	
	private void Awake(){
		BuildingManager.Current?.AddBuilding(this);
	}
}