Well, to my understanding it's a social network for languages. So you can do all or any of the following:
- search for language exchange partners (you teach someone your native language and they teach you theirs) or study buddies (you both learn the same language and practice together) in "Find a Language Partner" or in "Language index"; add them as friends, then chat with them, exchange e-mails etc.
- join groups of people who learn the language you want to learn, or the one you want to teach/help others learn; or groups formed on other criteria - see Groups;
- browse "Resources" and "Files" for (links to) courses, dictionaries and other resources for various languages;
- go to Answers to ask or answer questions on various language issues.
I might have missed something. Good luck!