Thats easy! first u need a camera if u dont know what that is you should learn a bit more. The camera needs to be adjusted to your first person type veiw -- distance, rotaion so on. Next u need to have a trigger like so:Camera - Lock camera target for Player 1 (Red) to (Triggering unit), offset by (0.00, 0.00) using Default rotation Copy that and paste as text. Its on map instalization. This is how the trigger should look Events: map instalization Condition: whatever Trigger: camera: lock camera to (unit)offset by: whatever, whatever using whatever rotaion. Next u gotta change his camera: So u just say apply camera object (name of first person veiw camera) If u do a cinimatic u have both triggers at the end of them or else it wont lock correctly. Stopping a palyer from unlocking: Every 0.01 seconds Condition: (If u wan cinimatics u should have a condition (bolean) that the cinimatics set to stop this trigger) Lock camera to (unit) offset by(whatever, whatever) And thats about all.
modeler got most of it. After you lock the camera to the unit though, you should lock the unit orientation to the camera. That will make it so that when the unit turns, the camera turns. That will save much processing time. (I am not positive, but you might be able to do the same thing with the lock camera to unit using unit's rotation, not default rotation, but don't quote me on that as I'm not sure.)