Turn Based Strategy Game - Character Selection and movement

Hello,

Can anyone show me how you would select an individual unit in a strategy game, using the mouse, and then, with a second click on the field, move it to that spot.

If you click on one unit, any other unit clicked before will no longer be active, but the unit you click will now be active.

https://www.udemy.com/course/turn-based-strategy-game-development/
Turn based game dev tutorial like heroes of might and magic