There are number of sites but best one is off-course w3school. It has demo option too which will let you know, what will be the output for the code you have specified.
Here are some tips on what you need to
learn hope it helps. First you need to watch tutorials and learn about HTML.
it and start learning.
If you want to learn web design online there are many sites available on the internet you can take help from the internet, mostly I will suggest to you W3school is the best site for learning web design or development.
There are numerous websites for learning Web Development. Here are the three websites which I tend to like.
2: Udacity: Most of the courses here are done in collaboration with Google, which is obviously a better thing. But the thing is that not all courses are free. If you want to learn all those advanced stuffs then pay some extra bucks which is worth spending .
3:Udemy : What I like about this website is that there are numerous free courses on Web Development. You can get an entire course, beginner to advanced only on Rs 600.
There are more websites like Khan Academy….etc.