I hope this is an alright place to post this, but I'm looking to join a RP. I joined the site around two weeks ago, have RP'ed for about 2 years, but wanted to start around the Free RP's to make sure I'm up to par for Casual. None of the RP's in the interest inventory area that I've posted interest in have really taken off. Any tips? Should I try going to the Casual Interest Inventory subforum and do my best there?

You should definitely look in all areas to see if something strikes your fancy, and if they do - ask yourself if you fit within that level of writing(Some are different based on the GMs own expectations), but Casual isn't hard at all to do. Best way to make sure you're ready for Casual is to do a Casual RP, otherwise it'll be hard to determine whether or not you can hang with them.

Keep looking and you'll eventually find one. I was looking for a few RPs to enter (and one or two didn't take off) before I found one that I liked. It's almost like looking for 2nd hand goods on Ebay. What's sold one week is not always the same as what is sold the next week. Also, talk to the GM and ask questions. Get a feel for the type of person they are and how the RP is going to work. My GM is strict for what she wants but it's good because she is also very lenient if it fits within her idea for the world. And best of all, Good Luck. :)