linux/self host newbies, now is a good time to get you a cheap server
Lot of sales for 4th of july (and ongoing ones) where you can pay $10-$14 for a YEAR of a small cheap VPS. Usually only has 1GB of memory, but that's plenty to play around with and learn. If nothing else, a good cheap ipv4 you can use for some port forwarding. There are lots of options, but I've used racknerd and ethernetservers which have been fine.
I have my own server at home, but I bought two small ones to start learning Ansible with in a risk free way. Eventually plan to redo my main server with a complete Ansible setup, really want to hop on that "infrastructure as code" train.
Try putting an RSS reader on their like FreshRSS! Or a bookmark manager such as LinkAce! Start your own personal wiki/knowledge base with BookStack! Try deploying them natively, then learn how awesome docker is and put them into a compose file. Add wireguard into the mix so your services can only be accessed via a VPN.
Now get yourself a domain if you don't already have one. Pro tip if you want to maximize the cheapness of your setup, you can get a .xyz domain for .99 cents a year! Just has to be funny numbers, but find some numbers that has meaning and its not bad. Now that you have a domain, put those bad boys in a subdomain. Tired of those pesky browser errors? Time to setup a reverse proxy and get yourself an HTTPS cert. Caddy is brain dead easy to do this.
I used it for a bit and enjoyed how well developed it is, but I moved onto something different as I needed something more freeform. If the structure of BookStack works for you, you can't get much better.
For me, something like PiHole for DNS-based Adblocking, as well as potentially a Wireguard/OpenVPN installation (via PiVPN potentially) for an easy adblocking VPN combination. Depends on the available bandwidth, however, but some lower powered applications, even up to a small personal Matrix Synapse server could be viable on 1GB Ram if not abused.
If you're thinking of hosting Matrix on that small of a server consider going with Conduit or Dendrite. They're not as feature complete as Synapse but they're substantially lighter.
Oh yeah, I briefly tried Prosody/XMPP (before a domain scalper stole a previous domain of mine because of a loophole with the TLD i chose) and it worked really well.
It's a shame Matrix seems to be the current hot new thing when, with a bit of UX polish on all the apps, XMPP would work just as well if not even better.
XMPP works pretty well, but it's not in the spotlight as much as Matrix right now. I get the sense that Matrix servers tend to be pretty heavy weight in comparison? Main problem with XMPP in my opinion is that there's no "one true app" available for every platform. There's something decent everywhere (with iOS being the worst supported, but getting better, Siskin is pretty solid), but it'd be really nice to have a decent app like Element everywhere so you could help your friends on different platforms better, and trust that they're getting a similar experience. Conversations is kind of an amazing app on android, I like Dino on Linux, Siskin is pretty good on iOS... Not entirely sure what's going on with Macs (I think you can get Dino to work, but otherwise I guess maybe Beagle?)... I'm REALLY not sure what's going on with Windows.
But, por que no los dos! A lot of us host stuff as a hobby, so it can just be fun to set up an extra thing if you've got nothing better to do :P.
Snikket (which is run by a Prosody dev) is aiming to be the "one app" of XMPP. Their Android version is, IIRC, rebranded Conversations. Not sure on iOS/macOS but I think they have something there as well. And of course their server software is Prosody with a few extra plugins configured by default. All FOSS