2D Isometric Tilemap Player movement by clicking mouse

Hello,
I just recently started to learn unity and C# (so i am very nooby at this subject xP ). I am making 2D isometric tilebased dungeon game and what my players to move by selecting the Player with a mouse and clicking on the tile and player has to change his position to position of that tile. I got to the point where I click on the tile and get the grid coordinates of that tile (e.g., Tile #20 (5,6,0)) and of a Player in grid coordinates. But then if I use transform.Translate() to my coordinate of a tile, player simply wonders off hell knows where =).

I know there are scripts on how to make player to move by grid using keyboard. And do I have to attach Rigidbody2D, Script to a sprite or a parent Player object?))
So guys can you help me with at least basic movement from current position to tile coordinate?
Thank you in advance.
Update: I use Vector3.MoveTowards() and its better but still player goes in wrong directions.

void Update()

    {

        Vector2 currentPos = theRB.position;

        Vector3Int playerPos = tilemap.WorldToCell(currentPos);



        if (Input.GetMouseButtonDown(0))

        {

            Vector2 mousePos = Camera.main.ScreenToWorldPoint(Input.mousePosition);

            Vector3Int coordinate = tilemap.WorldToCell(mousePos);



            var tilePos = tilemap.GetTile(coordinate);



            Debug.Log(tilePos);

            Debug.Log(coordinate);

            Debug.Log(playerPos);



            theRB.position = Vector3.MoveTowards(currentPos, coordinate, moveSpeed * Time.deltaTime);

        }

Btw, for some reason I cannot add my code in here, it says that my content seems like spam.