Congrats on picking things up and really ramping up your playing. I think you have a great idea getting out to an open mic to start getting out there. Especially when you are starting out, there is nothing like the excitement of performing for an audience.
A few years ago, I was in your position but playing in a band rather than a solo act.
Some random advice based on my experience...
- If you haven't already done so, scope out the open mic venue as an audience member. This way when you come to perform, you will know what to expect.
- Be sure to practice the songs you plan to perform a LOT with the gear you plan on using. If you plan to stand and perform, practice standing up.
- Though you strive for perfection, don't expect it. Don't let a missed chord change, a bum note, fumbled lyrics, or anything like that ruin the experience. Have fun!!!
- When you are practicing, play through your mistakes. On stage, there is no stopping and starting again.
- Choose songs you can play really well and are 100% comfortable with. You will have enough to stress about...you don't need to stress about performing a song that is quite challenging.
- Stick around to watch the other performers. There is nothing worse than going on at the end and there are only 1 or 2 people left. They sat and listened to you, you should return the favor :).
- Talk to your fellow musicians. It's really great to get to know others that have the same passion as you for music. You may very well find a collaboration partner!
- Be respectful to the people running the open mic.
- Understand that each time you get on stage it gets easier. If you are a nervous wreck your first time out, don't let it deter you from going out again.
Hope some of that helps. Have fun and let us know how it goes!!