Setting up a home cloud with Raspberry Pi

I have set up Nextcloud in a Raspberry Pi running here at home. My goal is two-fold: firstly I want to have a file sharing solution that works across devices and operating systems, and secondly I also want to know where the data is (and by extension, who can access it!). Calling this a "home cloud" is a bit of a stretch: given how humble my goals and the machine it is running on, it's more akin to…