I want to create my own site and I wanna know what all are the programming language I need to learn to build a website. I want to create both design and scripts. What if we want to create web app?
There are various programming languages like PHP, java, HTML, etc. But now a days website is easy to make. Wordpress have made it simple. Just download wordpress which is an open source software and install in it on your server and start making websites/blog.
Your original question is too vague. It's like asking "How can I make money online?" - there are thousands of answers and most of them are complicated. So you need to figure out better questions to ask. You could start with things like "What kind of site do I want to run?", "What do I want to achieve with a site?" and things like that. Then you can go looking for existing systems to avoid reproducing something that's already been done. The big CMSs - WordPress, Drupal, Joomla and so on - are all capable of being bent into almost any shape, to do almost anything. Of those, WP has the lowest learning curve for the basics, though you'll end up learning (at least) php if you want to build your own theme and plugins. All the big CMSs also have enormous communities of programmers who have either already written the code you need or are willing to help spot bugs, point you in the right direction and so on. Never underestimate the benefit of a supportive community! The only piece of advice I would offer beyond this is "start small". If you decide to script your own bespoke website, you'll have to learn HTML, CSS and at least one programming language (php, etc.). You'll find that even a "simple" bespoke project turns out to be enormous... so start small. Build on an existing system so you can take "baby steps" in programming. That's exactly what I did in learning to write WP plugins: WP handles all the basics so I don't have to worry about them, and I just wrote some code to do specific things that WP doesn't do on its own. Shallower learning curve, tons of predefined functions to use, data already structured, loads of benefits to make the process easier and more fun (and less frustrating).
The idea seems good, but a 1.4Mb landing page with all those wastey-spacey widgets and flibbety-wibbles? And everything on one page? Seriously?