Here's how do it.
1. You can send friend requests by clicking in their name, then press the button on their cover saying "friend request".
2. You can add a group by pressing "Add Group", then you can wait for your group to be approved. You can also join groups by going to a group and pressing "join group" by the cover. If your the owner of the group, make sure to check for requests and approve them, or decline them (that's sad).
3. Just comment or post. Easy. Dont think I need to explain.
4. You can send private chats by your inbox.
You can do many things, and if you have questions, feel free to ask me!