How to send messages to friends and join them

First of all you should friend someone! click the little player icon with the + Sign! If you know a players name you can type it in the Search bar! If it comes up you can click Add Friend and see if they accept or reject it. If they do accept you on the right of your screen you should say an Icon with there Avatar on it! By clicking that Icon a Messenger will appear, allowing you to message them with the bar. Type in what you want to say and click Enter and it will send, now wait for a reply! If a text appears underneath the icon saying In Game Session then there playing a game. Clicking the Icon will let you join them in there game! If it says Creating a Game then there building their own game. Clicking it won't let you join unless they invite you, we don't want raiders!