After many weeks of toil, I have finished updating my website's back-end configuration, and everything seems to be mostly stable, knock on wood.
I originally tried using Docker to set up the website, but it made it really difficult to make any kind of configuration changes, and i was going to have to install NGINX outside of docker anyway, to get SSL working, so I decided to just build the tech stack myself.
It was a gigantic pain in the ass, since none of the guides fully worked, so I kind of had to figure it out as I went along. But in the end, I got everything working, including SSL and site caching. Plus, I now have direct SSH and FTP access to the site, if I need to mess with files and such.
As for the site theme, I got the archive page working, and updated the travel pages so that they can each have their own background, and the posts are in reverse chronoological order, so it's easier to read through them in order.