Very confused, simple question

Hello Sitepoint. I am a new user here, trying to find my way around the forum. I feel this is the best forum for web design and development and hope to get the assistance I need and contribute to it as well.

I have a question that is probably very simple:

So I know javascript, html and css (the basics). Thats great for basic we design. Im trying to learn how to create web applications similar to this:

//youtu.be/R4D-Byvq5cs

Things that are “live” as I call the. Containing drag and drop features. A mobile website builder, similar to the one above, is what im trying to start with. Now I dont know which direction to go in, what langauge to learn, if it can be built with what I already know etc. and was hoping somebody could help me (tutorials, guides, advice, suggestions, etc.)

P.S.
Not to be offensive, but Im trying to build premium/professional web applications and would like information that will take me in that direction. Thanks in advance!

I think you are trying to do too much if your knowledge is only basic at this point. It’s not realistic to build a user interface for a website building application if you only just know the basics of html, css and js at this point.

I’d say you should work on other projects to learn and hone these skills first. Then work on getting to know php & mysql, and from there you may be able to gradually build the knowledge to build something like this.

I reckon it would take you a couple of years learning these skills to realistically build something like this.

I agree with @aaarrrggh on this one. To build app like mentioned you will need knowledge way above basic.
To move in that direction you can start with checking out some javascript MVC, which will help you to make frontend interactions realtime. Here’s a nice overview of different frameworks http://addyosmani.github.com/todomvc/
Besides frontend skills you will also need to learn some backend language, with php being the popular choice, I would recommend considering node.js which uses javascript, therefore you can learn and use javascript for frontend and backend as well. On top of all that you will also need database - start with MySQL as it’s most popular open source database.