Confidence is something that can be increased. If you have low confidence, it can be raised, and I believe there are two ways of doing so.
#1: Daily actions
Confidence is something that you must earn DAILY. Your level of confidence for the day starts off low, but through action, you can increase it.
You increase your confidence each day by the actions you take that are in alignment with your ultimate vision of yourself and that are aligned with your top values. If you wake up and start getting into alignment-based action, you will build up confidence after you complete each task.
My morning routine is filled with tasks that are aligned with my top values. After doing these tasks, I start feeling the confidence build up. If I did not do them, I would not be as confident that day.
Confidence is something that must be cultivated daily through action. Find tasks that are aligned with your top values and vision of yourself, then figure out how to incorporate them into your day to increase your confidence.
#2: Becoming your ultimate self
Your baseline level of confidence is the confidence you would have if you did not do anything to earn it for that day. This is determined by how long you have been living in alignment with your vision of your highest self. When becoming your highest self, you will become someone you respect. When you respect yourself and what you are creating, you will have a higher baseline level of confidence because you respect what you are. This self-respect is where the confidence stems from.
If you see yourself as being in better shape, but have not done anything to make that happen, you will not have as much confidence. If you followed your vision of your highest self and started losing weight you would naturally have more confidence.
I respect people that are in great shape and have a body full of tattoos. Over the last few years, I have been working on both those aspects, I have lost weight, got in shape, and have tattooed a lot of my body. I now walk around with a higher baseline level of confidence because I am what I respect.
Figure out what you respect and admire and work on becoming that.
Confidence is something you must earn daily. If you want more confidence do things that are in alignment with your values and the highest version of yourself.