"Friendzoned" is just a teeny-bopper way of saying someone you consider a friend is not romantically or sexually attracted to you.
Guess what? The overwhelming majority of people are not going to be romantically interested in you. That is life. Even if you are an attractive person people don't walk around throwing themselves romantically at each other and are a bit choosy about how this happens.
The biggest takeaway should not be how to get the unrequited feelings you want, frankly there's not a whole lot you can do there other than the basics.
What you should do is realize that you can't control this, and that you need to be willing to move on if you don't get her to feel the way about you that you want. It will happen many more times in life and there is no magic secret to make people feel the same way about you that you feel about them, unrequited feelings are a fact of life. We all have had "dream girls" or "dream guys" that we had a phase about. Sometimes it works and a relationship is born. More often it doesn't and the secret is accepting this and moving on. Not trying to will it to happen.