I want to host my website in my raspberry pi, I've read that I would need a web server software for this. Which one do you recommend? It won't be a complex website.
I always love Flask for this, it's a super simple python web server that is basically fully batteries included, just write a couple lines of python and throw your html in either /static or /templates, depending on whether it's dynamic or not, and you're live. It's not gonna move mountains but it's not meant to.
I currently read that Flask is not good for production. They say I can use something like waitress. If possible I'd use something like that over nginx for simplicity's sake.
Much lower and you shouldn't care. As long as you're serving less than one request per second, you will not need to care about performance. If you do, sanic and vibora are drop-in flask replacements and they are both much more performant.