So I was going to install a simple HTTP server program on my laptop that I could use to upload a website. This website should then only be accessible to those who also have access to our WLAN.
Does anyone know how I can do this?
Just like on any other computer - just install a web server (apache, nginx, tomcat, …).
Of course, this requires a constantly running notebook. It can make more sense to do this with a Raspi.
I don't want to let the server run long term, just now and then
Yes, but a Raspberry would make more sense and save electricity
I just want to try it before I spend money on it.
Okay, what do you want to do with it?
I have a website with a chat service and I would like to test it with my brother.
For a website with chat you will probably need an interpreter language (probably PHP) and a database in addition to a web server. If you only want it to run on the local network, you can install xampp.
Xampp can also be used on the Internet IF you secure it beforehand…