I really want to have a more bubbly, confident personality. Help?

I'm kind of shy around strangers. I just moved and because of this, I'm having trouble making friends. I really, really try to be confident and bubbly but when I'm actually in the moment, I freak out and just get awkward. I don't know if you know who this is, but Lea Michele (Rachel on Glee) is kind of my role model. When I watch interviews of her or even look at pictures, she always seems to have this genuine smile and bubbly personality about her. I really aspire to have this. So, how can I get this personality. I really just want to come out of my shell but I always freak out when I'm in public. Will this just naturally come with maturity or is it something I can work on now? I plan on being some kind of doctor so I'd really like to have a great personality.