Crowdfunding product page

This project was a struggle for me, especially with the overlays, and getting the submit buttons to show the correct information to the DOM. Glad I was able to learn a lot from this but I still need a lot of improvements, especially in my JavaScript code. I overcame my struggles by breaking down the down to its core and starting the code over again.

How can I improve my JS code? Are there any methods, or elements I should practice on? Is my code easily understandable/readable?

All feedback is greatly appreciated thanks!