Adobe Extension Builder 3 Problem

Hello everyone, saw that we could create our own extensions in Creative Cloud ! Well I tried with a little knowledge in coding. But there is some little problem, I created my first panel in Illustrator, it appeared in the Extensions Window but I when i click on it it completly empty ! I knew that I needed to write some code to change the UI for example, did a first test, just added some text in the index.html file and it's not working... It's been almost 2 weeks that I'm trying this and i'm not gonna give up ! Got some screenshots here, working with Eclipse. If you need more screenshots just ask.

Help here would be highly appreciated.

Virgile