You can have your own user page (create it using the button above); it is all about you!
The two easiest ways to interact with other users are to join the forums or leave messages on users' talk pages. Remember to sign all of your posts, so we can quickly tell who left the message.
(Hint: Use four tildes (~~~~). This will automatically produce your username and date. You can also use the 'signature' button in the edit toolbar.)