That's awesome!!! Trust me, you will never feel totally ready to perform in front of an audience. It is an incredible experience though! You just need to go out and do it!
For your first experience, you want to set yourself up for success, so performing in front of a sympathetic audience, such as an open mic, is a great way to start.
In the last year, I played in a band at a couple of open mics and for the first time ever improvised a guitar solo in front of an audience. I was about the most stressful thing I've ever done, but it was an INCREDIBLE experience. Now I'm trying to find a way to keep playing in a band and getting in front of an audience. It's addictive I tell you...