If I were starting out, I think I'd first branch out into some people I know but maybe not well enough to call friends. If you know someone who works in a fast food place, ask for a few minutes of their time during one of their breaks.
I tested a lot of my patter and presentation on guys at a local firehouse. They've got a really stressy job, and not many people show up there and go "hey guys, I thought you might like to see a few card tricks if you're not too busy." Admittedly, for a pretty girl it might seem like walking through lion country wearing a sirloin suit, but if that's a worry, take a guy along. Brightens their day, gives you a chance to try out material on an audience that's totally unfamiliar with you. I told 'em right at the start "My goal is to become a professional. If you guys notice anything, see anything fishy, bust me. I won't get mad at you because you'll be helping me." and stuck to that.
Any opportunity to do your material for a live audience is a chance to confront the jitters and realize you're not going to smother to death, get through any mental blockages you might have in public speaking, and allow you to connect with real people who don't have any obligations to you personally. With firefighters, police officers, etc, you're working to a crowd who usually only see people because something's going horribly, that's a plus too.
You'll do great. My personal rule is a minimum 10-12 hours on each effect before I try it on an audience. It sounds like a lot, but you need to have your patter worked all the way out and you need to have seen whatever glitches can pop up in the routine before they pop up in a performance. When you've got that much time with an effect, you come to know it well and develop a sense of how well it's going and that's invaluable when it's before an audience.