What are the required technologies to start Web-Development back-end with c# and .net? [closed]

I am currently an intern developer at a company and studying CS(3rd semester). I have experience doing Full-Stack web development using React for the Front and Node.js/Express for the Back-End. But I would really like to gain some experience in back-end with c#.

I thought I should post to ask what exactly are the required technologies that someone should use in order to create the backend part of a Website with c#? I have read that .Net is used, but I don't know where to start tbh(and what is the difference with asp.net :S). Any nice resources to recommend? And can someone maybe give me a list of the essential technologies to learn in order to start coding in this way?

Thanks!