Please Help. Not sure what to use to make this

Let’s say I have three columns labeled 1, 2, and 3 and I also have objects A, B, and C you can click on and it will go in a column. So if I click on object A first it will appear in column 1, and if I click object C next it will show up in column 2 and so on. So the order the object is clicked is the order it will show up in the column. Thanks for any help.

You could use something like this and attach it to every object A, B and C.

public class Columnizer : MonoBehaviour
    {
        private static int _currentIndex = 1;

        private void OnMouseUpAsButton()
        {
            GameObject[] column = GameObject.FindGameObjectsWithTag(_currentIndex.ToString());
            if (column.Length > 1 || column.Length == 0)
                throw new System.Exception("More or less than one column tagged as " + _currentIndex);

            _currentIndex++;

            transform.SetParent(column[0].transform);
            transform.localPosition = Vector3.zero;
        }
    }

Keep a queue of your columns, whenever you click on an object just dequeue a column and now you have first free column. If you want to reuse them, just enqueue back a column when you remove object from it.