To unlock the Command and Control trophy in The Division 2, you will need to discover 20 control points. Control points are marked on your map with a red flag icon, which will appear when you are in close proximity to one.
The control points are heavily guarded and will reward you with a decent amount of XP and occasional fast travel points if you capture them.
For the Command and Control trophy, however, you won't need to capture them. Discovering 20 is enough.