need help how to toggle between the world map and tactical map really stuck after clilking everywhere. thanks

To get back to the world map, click on the button in the upper right corner of the screen. If that is not clickable, there are still enemies around.

To get into a territories tactical map, select your squad and then right click on the icon of a place you have already conquered. The team will automatically enter the region. Or you can order your team to move to a destination occupied by the enemy. Once your team reaches the outskirts of the red square surrounding that area, the view will switch to tactical map.