How to unlock: You have to finish the APEX multiplayer tutorial mission.
Commentary: To get it, go to the multiplayer mode, select and play through the tutorial mission. Once you're done, you will be given the trophy.
The method to acquire this trophy is fairly simple and will at the same time allow you to learn basics of the multiplayer mode of the game. Enter the multiplayer mode (either from the main menu, or by going into the options screen when you are in the game), go into TUTORIALS and start the middle mission, PLAY TUTORIAL MISSION, as shown on the above screenshot, to begin.
You have to complete this short mission, during which you will complete all of the possible objectives that you might stumble upon during a multiplayer session. Once the mission is over, you will be given the trophy as soon as you are back in the main menu.