Move a selected object.

Currently i am working on an RTS game and I want to select an object and then move that selected object but the problem is when i click somewhere in the terrain then all gameobjects began to move to that point . So how i can achieve this . And my code is this. Any help will be appreciated . Thanks.

using System.Collections; using System.Collections.Generic; using UnityEngine; using UnityEngine.UI; public class OnMouseMove : MonoBehaviour { GameObject obj; %|-1720431080_2|% %|746481839_3|% %|-1051463637_4|% %|-1988011646_5|% %|2050251650_6|% void Start() { %|783189557_9|% ismove = false; } %|1837895370_12|% void Update() { %|-1673666550_15|% %|-1029015290_16|% Ray ray = Camera.main.ScreenPointToRay(Input.mousePosition); %|-764338503_18|% if (Physics.Raycast(ray, out hit)) { obj = hit.collider.gameObject; } %|1616007807_23|% if (Input.GetMouseButton(0)) { %|-1342988185_26|% } else if (ismove) { %|610140773_30|% %|1993733279_31|% %|1503594703_32|% void Set_Target_Positoion() { %|-1926264001_35|% RaycastHit hit; if (Physics.Raycast(ray, out hit)) %|-577530960_38|% TargetPosition = hit.point; %|906981630_40|% ismove = true; } void MovePlayer(GameObject obj) %|1722478830_44|% %|148729395_45|% %|785444710_46|% %|1751700689_47|% %|-579865991_48|% %|-85349588_49|% %|1369942042_50|% %|-1020095342_51|% }