I'll apologise now for the tiktok link, i know how much this place hates tiktok but here is a woman who did a deep dive and found evidence that the company actually changed their logo and tried to scrub the existence of the Cornucopia from the internet to distance themselves from Bad PR.

https://www.tiktok.com/@dimelifting/video/7311071477732838687

Likely not the solution you're looking for but a buddy and i link a folder via syncthing and anything added to one side shows up on the other.

To play off what others are saying i think a mini pc and a stand alone nas may be the better route for you. It may seem counter intuitive to break it out into two devices but doing so will allow room for growth. If you buy a creeper bare bones mini pc and put more of your budget towards a nas and storage you could expand the mini pc without messing with your nas. You could keep the pi in the mix for a backup if your main pc is down or offload some services to it to balance performance.

It's a great software to run. I like to watch youtube tutorials that explain things step by step so i can understand what happens. If i find a good video i'll see what other software that channel may have a tutorial on and if that software may interest me.

You could set up a dns based ad-blocker like pihole and a vpn like wireguard to tunnel your phone back into your home network so you have ad-blocking on the go, too. That's a semi beginner protect with plenty of tutorials to pick from.

You could run nextcloud, syncthing, or immich to make your own cloud at home but that might need more than a basic pi setup.

Learning how to use your pi to run a reverse proxy to a self hosted blogging site would give you plenty of hands on starter experience. Run docker and portainer and mess with docker config files from a webgui to see what work and what doesn't.

As a self taught self-hosting enthusiast i wouldn't recommend ansible to a beginner. I know that sounds backwards as absible makes everything easy and does all the work for you but that's also part of the problem. It would be like jumping behind the wheel of a self driving car without knowing how to drive at all. When (not if) something goes wrong it could go wrong hard and you'd lose the whole instance.

It's better to start with some other self hosted projects that interest you to get a feel for the process and software like docker then work your way up to bigger things like lemmy. I consider myself fairly versed in the process and lemmy still gave me some issues to set up and my pixelfed instance still won't federate despite my best efforts. I'm pretty sure i know the issue, i just need to get around to fixing it.

Last thought, the raspberry pi is a pretty impressive little pc for it's size and price point but you might find yourself quickly burning through resources depending on the number of active users you have and how heavily you use it.

Underrated explanation, you held it finally click for me. I consider myself a fairly educated person but just couldn't wrap my head around what made it so special. Correct me if i'm wrong but my understanding is the server uses the public key to encrypt a challenge code that can only be decrypted by your private key. You get an on device prompt to approve the process and the rest is done under the hood.

To go further on this, is the public/private key a mathematical relationship? What ties the two together to make them useful as a pair?

AudioBookShelf is a beautiful podcast option. OP would have to fully migrate into it but once done it'll let you listen to an episode on pc, pause, then resume from the same spot on mobile. It'll auto grab episode as they come out and store them on your system for streaming or local access. The android app is pretty good and i know webapp works well on ios

I'm never a fan of virtualizing network related items for the sake of redundancy, if your server goes down the rest of your network can keep doing it's thing. That being said, with the hardware you have on your hands i don't see any solid atonemen argument for bringing in more hardware.

Proxmox is a great base for you to really ramp things up and i'd recommend looking into pfsense as a routing/firewall solution. There's a bunch of great youtube videos that can talk you through setting it up and using it as your vpn point, adblocking, reverse proxy, and so much more.

I'm no expert but my understanding is all drinking cans are lined with plastic to withstand erosion.

https://www.ehow.com/facts_7390219_metal-cans-lined-plastic-coating_.html

Everyones process is a little different but that sounds unnecessarily complicated. See my other comment about the arrs through docker. You could probably do it all in a single compose file.