Could anyone give me some advice on what I should focus on at this stage of my life? Earning more Money or gaining more Experience?

Gaining the right kind of experience!

Definitely internship if its of a relevant field. The credentials and experience you get at this point of your life will be valuable, and you will also gain more insight into the industry as compared to your peers. This can affect how you see your school life in the future and the choices you make.

You are waiting to go university. I think experience would be better as the experience and knowledge can not only help in the future, can also be useful when you enter university. If you are in need of money, good paying job will be beneficial but getting experience would be a better choice since you are still young.

I would recommend learning and gaining more experience. Once you have the required experience with you, you can start making more and more money.