jamulus VS Ampache

I'm not 100% this is the right tool, https://jamulus.io/ but something fitting your needs was covered in a 2nd hour of office hours a few months back. https://officehours.global/

Ninjam is very cool and mature software with a nice community. However, not everyone can get used to the idea of playing one bar behind everybody else. While it can provide almost no-latency experience, some people just can't wrap their head around it. And, of course, it prevents rhythmic development and severely limits freedom of improvisation. For static beats and repetitive harmony it works great, though.

If you'd like to try jamming completely simultaneously, try Jamulus (federated client-server architecture) or Sonobus (p2p). Both are free software and work very well, at least as well as physics allow. In-city jams are hindrance-free, close cities and even close countries are usually painless, as long as everyone's on Ethernet, of course.

https://jamulus.io/

https://www.sonobus.net/

There is Jamulus. https://jamulus.io/

For "normal" musicians jamulus.io seems to work. https://jamulus.io/

https://jamulus.io/ This tries to connect musicians with as low as possible latency.

I know a bunch of people the use Jamulus and are very happy with it.

If you like having a music server on the lan instead of local, consider setting up an Ampache server. https://ampache.org/

Did you check Ampache? Didn't tried yet (it's on my wishlist), but seems it support webdav.

It's a lot. I would suggest starting with Linux. Get a server edition, with no desktop environment, since you won't have one in a container. A decent first project I tell juniors to do is get a LAMP/LNMP stack up and running in a virtual machine. It's even fine in VirtualBox. I don't know if you have any old MP3's laying around, but Ampache might be a fun project to try and get working. Get comfortable with the Linux command line.