Awesome SelfHosted is a great place to start looking: https://github.com/awesome-selfhosted/awesome-selfhosted

Radicale’s official documentation didn’t help me much, so I followed some youtube video (by “Awesome Open Source”) where you use a docker image instead of a python venv + pip install.

For Immich, official docs were fantastic!

For Nextcloud, I followed Learn Linux TV’s “How to Set Up Nextcloud on Ubuntu 24.04 LTS” (though I used Debian, not Ubuntu)

There a million ways, and you will probably find tons of tutorials each different - Docker, Docker Compose, native install, VMWare, Kubernetes, Portainer, etc. I recommend starting with a clean machine - preferably with an attached monitor - and installing your favorite Linux distro (Ubuntu is among the easiest), getting Docker and Docker Compose running, and familiarizing yourself with these technologies.

Then you can start with a simple app like Paperless (document digitization), Vikunja (TODOs), BookStack (wiki), or PrivateBin (pastebin), getting it running and persist state over a period of time, then setting up a reverse proxy so you don't have to use IPs all the time (with just editing your hosts file to point a URL to IP of your machine), and then it is a free world.

Of course, having the whole setup secure, independent, and easily manageable is partially eyperience and partially understanding your needs.

You will probably even find whole ready-to-deploy git repositories that are easily configurable, so you can go with that too.

I went down the route of a Raspberry Pi 5 and Installing Dietpi as the OS. Dietpi has loads of recipes in its main app that makes it easy to get going, plus if you install docker you have a huge range of stuff to try.

There is a learning curve but it's not too steep and I've enjoyed it.