Making a website

Hi /tech/, what would one have to learn in order to be able to make a website that has a couple hundred pages and a forum. An example: You enter the site for the first time and it detects that so it asks you to complete a questionnaire which then leads you directly to links to specific sections chosen on how you responded. Of course, the user would have the option to not answer and be redirected to the homepage.
So, what should I learn specifically to be able to make something like that and where would I find such information?
The hardware required for maintaining something like that would also be nice to know in regards to pricing and such considering a maximum of 150-200 people simultaneously browsing.
I'm sorry if the questions are stupid or shouldn't be asked here.

So HTML is all I need? The database and all that can be covered by using it? Wouldn't I need CSS and Java for example for the forum, login and all that? I'm not sure how you link them together. Is all the code put online and refferenced in the pages via their address / extesion?
Also I'd have to make all the pretty assets I guess.
To practice, I could just make the basic pages locally? What software would you reccomend? Seeing the source of other websites would help me prevent common vulnerabilities?