The safest thing you can do is direct download from file share websites, but nobody says where these websites are.

Until some legal entity decides to raid the servers. Pray they do not keep logs of IPs. Though usually this may be (to some extent) a gray zone in some countries.

If you want to torrent files, you need to subscribe to an exclusive private tracker

I download anime almost exclusively from nyaa. SubsPlease, Erai-Raws and many others are borderline there within 2h from release.
Private trackers allow for even higher quality by applying a ruleset like only remuxes and maybe they only allow a certain bitrate to have it classify as a remux on their community.

. To get access to a private tracker, you need to get lucky, or you need to go through a painstaking process of levelling up over months and months of seeding torrents from semi-private trackers until you get to an actual good one that may or may not have the content you are looking for.

No need to level up. Some more exclusive trackers may (or may not) open their doors during an open signup. But this is like any exclusive club. Either you stay a "pleb" in the open field or work for acess to the hifher club. Don't imagine for a second you could just enter the exclusive area in a high roller casino without a few hundred 10k chips. :p

If you don't want to do this, you need to pay for a UseNet provider, then you need to register for a similarly exclusive UseNet index service, probably paid as well. There is no guarantee you will find what you are looking for on here either, and there is a chance that your download will fail.

Usenet was always paid in the recent years.
Paying an indexing service is not mandatory. I am signed up to 4 services in the free tier just fine.
That you will not find stuff there is just as likely there, in P2Pworld as in the open web DDL or the privately shared lists world.

Whether you are using torrents or UseNet, you need a service to help you find the content in the first place, for example Sonarr, Radarr or Lidarr. Something called Jackett also fits into this somehow and apparently links to whatever indexes you are using.

What?
You can search the sites just fine on their own search engine. The *arrs and jacket/prowlarr are just unifying the searching into one engine and the *arrs parse and categorize your searches to help you find the stuff you want.
As I said: You can either search TPB manually just fine, oooooor you plonk it into prowlarr and have it synced to your *arrs.

• If you are torrenting, you then need a torrent client such as qBitTorrent to actually get the files.

• If you are using UseNet, you need a UseNet downloader such as jdownloader.

To browse the web, you need a web browser?
To use a computer you need a storage drive?
To use anything you need electricity.
So what's your point??

Alternatively, for either option you can pay for a Debrid service such as Real-Debrid or Premiumize to download the files for you, if you send them the links. Besides protecting your privacy and your bandwidth, these services are also great for bypassing the limits on the elusive direct download sites nobody can tell me any more about.

Any user logged to an exclusive community and uploading to something like those services are borderline stupid. lmao!
And they probably risk their account from being banned pretty quickly for breaking seeding rules They may function like a remote qbittorrent with a nice streaming interface. You basically pay someone to give you a pretty interface. Same as a seedbox, but you have no power over what you can/can not do :p

but this shit is so confusing. It is harder than paying for drugs on the dark web with illegal crypto currency.

Absolutely not. You just may be having issues understanding the material. Nothing wrong with that though.
I am still having problems understanding some concepts of for example VLANs, (v)SANs and software defined storage.

I just wanna have my own home streaming service.

Easy:

• Download and install Jellyfin (or Plex if you want to get shafted. Just donate the same amount to the Jellyfin team).
• Organizing: Download and install sonarr (tv)/radarr (movies)
• Torrent: Either wait for access to TL during an upcoming holiday like easter and monitor communication channels or watch opensignup websites.
• Usenet: Sub to a few closed communities. Same as the torrent way.
• Downloading: For torrent: qbit, for usenet: sabnzbd.
• Indexing: Prowlarr as the all-in-one solutiom.
• Download: Either search prowlarr through it's own interface or through sonarr/radarr ooooor just download all yourself from some DDL page or rip from other (pirate) streaming sites via plugins and organize it via the *arrs.