Yeah, I just don't know how we come back from this. It's not like the sane among us are suddenly going to decide to go along with fascism, nor is that 30+% that somehow control the narrative going to stop being the literal worst all of a sudden (see: post-Reconstruction).
So we… Balkanize? Hold US Nuremberg trials and actually do something about the priblem, assuming we can get to that point?
We all got to learn somewhere!
Lot of good advice here, but sometimes people forget what it's like to be a beginner. Since you don't know what you're doing, I would recommend not trying to host things on your home server and access it from the outside world. That usually involves port forwarding on your router, and that comes with a lot of risks, especially if you don't know what you're doing. Others have mentioned it, but a better option when you're starting off is to rent a vps and host your software there.
Squarespace might work, but my guess is it'll be easier to transfer your domain elsewhere. You can follow guides for that online and it's pretty straightforward.
Having a vps, a domain name, you're most of the way there. On your vps, you'll want to install a reverse proxy, which is what routes incoming urls to the right place (nextcloud.domain.tld goes here, calendar.domain.tld goes there).
Docker is another thing I'd recommend learning as a lot of what you'll self host will likely be in a Docker container. I'd watch a few YouTube videos to see how it's done. This channel has some great videos, and there are others out there.
It seems like a lot, but learn a little here and there and don't expect to have this all working overnight. You'll get there!