Hi all,
I am in my early 30s and currently have a great job as a multimedia specialist for a government agency. I am basically a "jack of all trades" and use the entire Adobe Creative Suite to create products. My strength is in Photoshop/CSS3/HTML5 and frameworks like Bootstrap. I have an above basic knowledge of JQuery with an extremely limited knowledge of PHP and Javascript. As someone that wants to get in to more front-end development, what are your thoughts on the order of how I should learn the following languages? How in-depth do I need to get?

PHP, AJAX, JSON, JQuery, Javascript