My first suggestion is that you read the story synopsis to familiarize yourself with what is going on. Then see what threads are open: currently you can be a passerby in the underground city of Piriingisi on Sullust and join in with Galen and Lumbiasith in "Thus Far The Miles Are Measured," or you can wander up to Paul and Shawn and Minna Manth on the streets of Mos Eisely in the "Shattered Green" thread; both of these are in the Complete Star Wars Universe forums. They might be easier to jump into, unless you want to be wandering around on Coruscant in the "Return To Tomorrow" thread, where Lt. General Sorben Tarnus is currently running Empire affairs.

BUT! I highly suggest you read the entire story synopsis first, so you know what's been happening around here. Then choose an open thread, read it so you know the details, and insert yourself into a thread; this is better than beginning a new one and hoping someone else comes along in it. (Which usually doesn't happen since characters are usually elsewhere.)

Read the rules and regs in RP HQ, and once again, WELCOME TO THE FUN!

There you will find the easiest entry into role play, as Galen and Lumbiasith are talking outside an underground cantina on Sullust...