Society today is blurred by what it means to be confident. People often associate the term with appearance and/or one's ability to socialize and meet new people, but I reckon confidence is what you gain from mastering a skill, which of course takes practice.
I see confidence in everyone, just observe anyone doing what they're good at. I watch a mother who struggles to interact with new people, yet oozes confidence when it comes to supporting her family. An introverted computer genius may feel inadequate to ask a random girl out on a date, but put that same guy in front of a computer and watch his confidence transmit.
Every single person has confidence and you can find it in those "time to shine" moments of life. Everyone is an expert at something, therefore when you want to tap into your confidence, look to moments when people turn to you for advice and guidance. Where your skills and abilities are strongest is where you'll find your pool of self-belief and what it feels to be confident.
If you feel you lack confidence, the first thing you need to do is be unambiguous.
I always get asked "how do I become more confident?" I tell you now there's no switch that you can turn on which will make you strut down the street, with your head held high taking on the world. The question needs to be specific, ask "how do I build more confidence in..."
People who miraculously appear confident can never hold onto it. Certain things you change in your everyday life may help you feel more confident, but only for short while. You need to build confidence piece by piece until specific skills are acquired, these skills will help you overcome your confidence issues in the long run.
Just like when you learn a new sport, you have to train and the more you train the better you get, the better you get your confidence grows.
So don't live life by the illusion of having zero confidence when you really do have heaps of it stashed away. If you ever feel inadequate, timid or unsure it's probably because you haven't acquired the skills you desire yet. Remind yourself of that now and again and build confidence with plenty of practice.