Can i develop website only by using html and css..?

Answer 1

Yes, you can...
For website only providing static stuff/information: on the other hand, if you want to develop website with some interactivity, you must at least use Javascript ^^

Answer 2

Probably not. If you want it to have the ability to press stuff and submit forms and such on then no. If you're only willing to write a page with text then yes.

Answer 3

You can make some static web pages for servers, such as Apache