I would recommend to you this Course for Angular on codeschool Shaping up with Angular.JS.
It took me just 2-3 hours to understand the logic of Angular.js and really helped me out with this.
Inonic is just a UI framework to give your App a nice look&feel. They have quite a good documentation on their site.
To implement this stuff in a phonegap application just go ahead and take a look at the ionic Get Stated Guide to download the ressources and implement them in your www - folder of your phonegap dir.
But first of all, start with the course ;-)