I started modeling as an adult. It's a misconception that you should be in your teens to start modeling.
There is no such thing as being too old to pursue a dream. There are models in their 30s (like myself) and 40s and beyond, working and making a nice paycheck.
In my teens, with a friend as the photographer, I would do practice photo sessions, being silly and practicing posing.
Practice makes perfect!
My first professional photo session, I was VERY nervous.
Thankfully the other women were very positive and made me feel comfortable.
They helped to make me feel comfortable and gave me some great tips.
Your confidence exudes in your photos.