I've been using YunoHost for some time. Cosmos seems good, too. Both do most of the stuff for you and should come with documentation. I think that's the way to go if you can't set it all up yourself, or lack time to maintain it.
I've also used Docker containers and plain Debian. I use NGinx as a reverse proxy.
I document things in text files (markdown). At some point it'd like to upload them with something like mkdocs or to a wiki. But since it's just me, having them just sitting in a directory on my laptop is fine.
Use something that's super accessible so you'll actually use it. I often just dump random thoughts or commands I executed into the textfiles and I have my text editor open all the time anyways. And then on the server I eiter use Ctrl+R and search through the shell history, or search in my documents. Doesn't need to be fancy, grep -rni "keyword" does it for me.