Built a custom WordPress theme
Wrote a Wordpress Plugin
Used an API
Used AngularJS
Designed an eCommerce Website
I had been doing odd jobs around the web for a few years by this point, mostly simple HTML sites, the occasional off-the-shelf WordPress install, etc.

A friend passed on a referral to a car salesman who was looking to build a page that delivered on-the-spot used car estimates. I spent a few weeks grinding my teeth against angularjs, until I eventually bought some time on codementor. My mentor cut through the confusion, showing me how to use the browser debugger, how to pass data back and forth between WordPress' PHP and the client-side JS, and generally putting my mind at ease.

I eventually wrapped my widget up into a custom WordPress plugin and shipped it for the client. It was my first "non-trivial" programming win, and I was on top of the world.