For email and calendar I’D probably look into proton. For other software tools i would start with services people like that you don’t have to manage other than be like the admin and as you go try and find alternatives and self host your own and teat it out. Maybe even something like digital ocean where you can just spin up a droplet that’s presetup for you and learn more and more until you’re comfortable to transition other people to it
https://possumpat.io/post/206685
Donkeys like them