Hi Thunderstorm,
Firstly let me welcome you to the burrow and secondly it's easy to get started with the site. To join a mob you just go down to one of the group topic areas (Tiny Kats, Willows, Phantoms.. which ever group takes your fancy) and within the group you will find some of the threads.
'Read this before role playing' is an important thread to read first, this accompanies our rules section and outlines how the site works and how members can respect each other and the RP.
Biographies - Just like other members you can create your own meerkat on a new thread within the mob area. Here you can describe their age, history, characteristics whatever you like to feel that your character can interact with everyone elses. Dominant character positions are currently filled however once you get established and comfortable then with the permissions of the site they can make challenges or step into roles that become available.
Ex. January 8th - Is the RP day thread. This is where the RP action occurs, once you have created a character you can then write about them approaching the chosen group looking for acceptance. Once the dominant Male/Female has accepted your character in the RP they then can join the group in daily activities and be a supporting member.
If you have any questions please feel free to contact one of the Admins/Moderators who will be glad to offer some friendly advice.