Because, contrary to what it might seem like, we ALL start out this way using Linux. Everyone makes the same mistakes, so its easy to retrace the logic once you understand what the commands you used to copy-paste are doing. OP you're clearly just making the switch and want to dive head-first into self-hosting as well as Linux, which will be a ton of fun, just try not to get discouraged as there is a lot to learn. Take it one step at a time, and try to understand the commands as there's really not that many, and you re-use these in many scenarios.

I see many people recommending Docker, which is great, but imho a little too early to dive in to if you haven't experimented with Linux at all. Docker is just a container of Linux inside of Linux, so you'll still need to use the command line, and it has its own set of tools. Just my two cents. Somebody else posted but this was the video that also made Linux 'click' for me:

https://www.youtube.com/watch?v=tc4ROCJYbm0&t=296

Don't be afraid to break things and start over. Have fun :)

I just wanted to add a small follow up comment because I remember being young and copy-pasting commands into Linux and eventually getting really frustrated. Therefore, he's a (brief) explanation of the commands:

1. curl is just an open source tool for making Web requests from the command line. It's a great tool to have in general.
2. https://repo.jellyfin.org/install-debuntu.sh the URL of a shell script from repo.jellyfin.org (Jellyfin's official website)

What is a shell script? It's a script that runs a whole bunch of commands by itself, so you don't have to copy-paste them from the internet. Basically the official Jellyfin people in this case made a file with all of the commands the computer needs to run to install the package. This is great because it means the people who made Jellyfin tested these commands and they're responsible for keeping it up to date if anything changes.

| bash The 'pipe' or | symbol in Linux is a cool Unix philosophy of 'connecting' programs together. You run one program, and tell it to pass the results to another program. In this case, you're telling curl to download the script at https://repo.jellyfin.org/install-debuntu.sh and then passing that file to bash (which is the shell program in the terminal that runs commands) and to run it as sudo or 'super-user'.

Hope this was helpful. The last thing you should know is the command you probably copy-pasted before made you add a source to the /etc/apt/sources files, which are basically just a list of sources for apt, the package manager to download from, and since the command was wrong or outdated, apt is complaining that the Jellyfin source was not found.

Seems like you followed some random AI generated guide like this one:

https://www.ipv6.rs/tutorial/Elementary_OS_Latest/Jellyfin/

Whenever you're downloading a Linux (or any) package, always try to look for the official documentation, like here:

https://jellyfin.org/docs/general/installation/linux#debian--ubuntu-and-derivatives

Where it will tell you to install Jellyfin on a Debian/Ubuntu based system is simply:

curl https://repo.jellyfin.org/install-debuntu.sh | sudo bash

and it also tells you that if you don't have curl already installed, either install it first or instead run:

wget -O- https://repo.jellyfin.org/install-debuntu.sh | sudo bash

which is their official installer.

If you want to undo what you did before installing (assuming you followed the bad guide linked above), just remove the file it created here first:

/etc/apt/sources.list.d/jellyfin.list

Just wanted to add me .2c here since I have some real-world experience with this and no dog in this fight. We're a small computer engineering company with 1 mechanical engineer on the team. We had designed a custom chassis for one of our products (first time we had ever done this), and were looking for quotations to build a prototype. After some research and recommendations, we narrowed it down to 3 companies: A German, American and a Canadian company; all were highly reputable. We were given quotes of $15,000 - $20,000 USD, and told our CAD files need to be heavily modified because some parts of our design were 'impossible'. We were also told it would take approx. 3 months to receive the prototype. Out of curiosity, we sent the CAD files to our PCB manufacturer in China and asked if they knew anyone who could build the chassis. They quoted us $300 and said it would take a week. We paid them, and honestly, we expected to receive garbage - it wasn't. We had minor complaints but overall, esp. for $300 and a week, it was excellent.

Switzerland..?

They seem safe enough to pass the EU’s safety standards, which are much higher than the US. Also this blanket “quality issues” argument without specific evidence is terrible. If we’re going off of quality in recent history, American manufacturing is down the toilet in terms of quality - just look at Boeing.

Not me but a good friend of mine met a girl and lied about his job. He was already working a decent job as a floor salesman while applying to be a flight attendant which paid more money. He told her he already had the position he was applying for, which he never got and it kept snowballing until he could no longer come clean without major consequences. For 6 months, he had to make up a fake flight schedule, fake work-related anecdotes, etc., Needless to say when he eventually came clean she ended things, and I suppose he learned a very strange but valuable lesson. It was pretty funny to me at least.

The US also effectively banned the entire Arab world from buying US GPU’s, I’ve run a business here for years that specialized in GPU compute at the datacenter level, and now we’re pretty much transitioning into a new line of business because of this genius policy, while existing customers in this region are also considering Huawei GPU’s as a possible replacement.

Is it just me, or is that foot rest backwards?

2006 was the peak

What an absolute farce of a “report” and an article

Have you even looked at any of the examples in SA’s case?