Are you a regular at any small bars? When I started, I was a semi-regular at a brewery. I saw a job posting, asked for an application, and they hired me on the spot because they knew me.
I would suggest you start slow. Bar tending full-time is incredibly exhausting. The hours are terrible, you're on your feet for your entire shift, and you end up eating more junk than you plan on. On the other hand, the money I make for part-time bar tending is ridiculous.
I would also think carefully about the type of bar you want to be working in. That's going to directly affect the money, as well as the quality of your shifts. For example, I work at a very successful brewery. I get to interact with people who are passionate about our product, and who travel to us to get it. I don't have to deal with people who are out to get drunk, or hook up, or pick fights.