I would recommend learning steps like this:

+ Update your php knowledge to modern standards. (i.e. autoloader)

+ Learn just some sass and use bootstrap 3.

+ Use something like laravel as a php framework or even smaller like slim

+ DONT get confused by the plethora of JS-Frameworks. DONT use build tools in the beginning. Plain old <script> tags for the start.

Start building something nice.

sign up on laracast.com ;)