How can i make a POST html page

Question

Hi, I always wanted to make a website that looks like any other website in the internet. A website where you can just click on a button POST or ASK A QUESTION just like in this site and make a thread where people can comment, but i have no idea of how to do this because i dont know how to write content

in html and save it permanently so it is saved as a whole html page. i have tried to use htmltextwriter,File.Copy() but no luck.For example, when i clicked in ASK A QUESTION, i saw textarea and lots of button so i could edit the html page howerver i want and then all of the stuff im writing right now will be written to an html page with the ability that users can see it and comment in(i dont know if it is required that comments by users should be saved in a database like on youtube comments). i think this is the only thing have left to learn about so i can build websites. I hope everyone understand what im trying to do.