You only need a server if you plan to serve the content in a sophisticated way (like Plex). If you just watch movies on your laptop then it's as simple as downloading the files and opening them.

Unfortunately, getting into usenet is actually not as technically hard as it is practically hard. First, some things to know about usenet:

• You pay for access to a usenet server, which has incredible speeds and doesn't rely on uploaders. There are many out there, and good ones are easy to find.
• Because it isn't P2P like torrents, there's no way for the studios to know who's been downloading anything. Typically the most they can do is send a DMCA to the servers, who auto-comply. Because of this near-anonymity, a VPN usually isn't used. The corporations would need to subpoena the server to get any of your info, and they're usually deliberately hosted in privacy-friendly countries.
• Now the hard part: knowing where the files you want to download exist on that usenet server, because even a small TV episode is often divided into 50+ smaller files. This is where NZBs come in. NZBs are small files that tell your usenet downloader where to find all the parts that create the bigger file. The usenet server you pay for doesn't provide this service for legal reasons.
• Therefore, you need to also subscribe to an NZB indexer, which is where you search for NZBs for shows, movies, games, etc. Some are one lifetime payment, some are recurring. Good ones usually only open their enrollment during very small windows, so it can be really tough to get into one. This is the biggest hurdle for most people. Even finding out which indexers are out there can be tough, as people generally don't blab about them in open forums, because they're the most piracy-adjacent and vulnerable to being shut down.

That said, once you have a usenet server to connect to, and an indexer to find what you want, then it's as simple as downloading the NZB file with a program like Sabnzbd, which will feel very similar to a torrent client. It downloads the various parts and combines them, so what you end up with is openable by windows (either media or exe). Everyone starts this way, and most users are probably content stopping at this stage too.

From there, however, some people get really advanced with it, like the person above running it on a separate server. There's software out there that automates TV and Movies downloads based on your preferences and which shows you subscribe to, same with music and even ebooks. Then there's Plex, which you may already be familiar with and which allows you to use your laptop or whatever to stream your content to phones, chromecast, etc., as well as share your content with friends to stream (requires paid sub I believe). It can be a little daunting to set everything up, but you're mostly just following guides because it's the same setup for everyone, minus changes in server URLs, username/password, etc. And once it's running, it really is beautiful. A show that I subscribe to that airs on say, Wednesdays 8-9pm, is available on my Plex by like 9:30 typically, without me having to lift a finger. I even get a notification on my phone that a new episode is available.

But to be able to transcode streams to multiple people in the house? Requires a somewhat beefy processor. And to keep your huge library of shows for years and year? Requires a lot of storage. Even more so on both counts if you want everything in 4K bluray quality. And it probably needs to be a dedicated machine--can't be gaming and transcoding from the same rig. But boy is it addicting building up your own enormous streaming service for friends and families haha. I hope you can see now why some people would get carried away with it.