It really comes down to what you want to achieve. I use the web server originally installed with pi-hole, lighttpd. It's a perfectly suitable service for what I need, largely to serve up rpi-monitor content. I have switched to using my own, newer build of it though. Search the forums for various other options that people have used. I think some have had success with Apache or Nginx. The largest problem you will face in running more than one, is port allocation. Also be aware, custom set ups will make troubleshooting more difficult and the pi-hole folks may not assist.
I would like to make a small website for personnal purpose. I mean I want to use it to have an access for some specific calculation (I have it in python script but I can adapt them if needed).