"The top left of your screen is called the Social Center. From here, you can see the number of players on your planet and how many of your friends and guild members are online. You can click on these numbers to bring up either the Who list, Friends list or Guild list.
Chatting: To chat, you just have to press the ENTER key. Then you can start typing and your text will appear in the chat box in the top left of your screen. When finished, press ENTER and your message will appear in a bubble visible to anyone within visible distance. There is a button to the left of the chat box that allows you to switch between General and Group chat. General chat can be seen by anyone on a world. Group chat can be seen by anyone in your group.
Grouping: To group, all you need to do is to right-click on another player. You will be given the option to send them a group invite. If they accept, their portrait will appear on the left side of your screen. You will be able to chat with them using Group chat.
Friends: You can befriend other players. They will be added to a Friends list accessed through your Social Center. Whenever a friend is online, you will be informed. To add a friend, right-click on another player’s portrait and select the option to friend them.
Guilds: You can join a guild. Guilds are groups of players that can use a private chat channel (Guild chat). Guilds are great to be a part of as they allow you to communicate with larger groups of people in order to form groups."