I self-host most of the things my family and I use on servers at home, and I document everything. Hopefully, the documentation will help.
I have a “death instruction manual” document with all the data and information my wife will need to access my digital life, including the documentation mentioned above, and contact information for people I trust to help her through the process of either managing those servers, or selling them for a good amount of money (there is about 90TB of storage in those).
I also try to teach her, and in time my son (he is too young right now), to manage those servers, but that is more of a long-term goal. She’s comfortable with Linux, so that’s a start.