Some servers, especially those using hardcore mode, can choose to disable the minimap. If the server chooses to hide it, you cannot enable it. You can search for minimap enabled servers using the advanced filters:

In Real Life...

Sight acquisition means transitioning your focus from the target to the sight of your weapon in order to shoot.

A scoped weapon puts the target and the crosshairs in the same vertical plane. There's no choice of what to focus on. An iron sighted weapon, however, has three distinct vertical planes - the rear sight, the front sight, and the target. The human eye can only focus in one plane at a time.

This is impossible.

The human eye can't focus on both the target and the sights at the same time.

This is correct.

When shooting, this is the picture your eye should see. The front sight should be in sharp focus, with the rear sights slightly blurry and the target slightly blurry.

Laser sights put the "front sight" in the same vertical plane as the target, however, your focus should still be on the sight. Transition from focusing on the target to focusing on the sight, then, while keeping the sight on the target, apply pressure to the trigger until the gun fires.

In the game...

All targets are by definition in the same vertical plane - your screen. Therefore, the game engine takes care of focus for you, always keeping either the target or the sights in focus as appropriate. In this case, sight acquisition simply means being able to distinguish the sights. It's flavor text, nothing more, because your eyes aren't really seeing the game in 3-D.