Session-Zero

My goals are to set up a Pi-Hole, Foundry VTT, and Plex Media Server server for friends/family ideally on one machine. I'd like to make Plex and Foundry accessible from my domain for ease of use. I'd also like to make sure the server is and remains safe for my users and self. I've got a server put together and Unraid installed. I managed to follow a couple IBRACORP YT guides to get adminer, mariadb, and krusader up and working in docker. I also acquired a domain and connected it to my server through Cloudflare. After I had done these things I took pause as I wasn't fully understanding what I was doing or why. I have a hard time with abstract thought and as a layman much of the explanations went over my head and I have no idea how to utilize the tools/apps I have installed and configured. I'd like some guide/tutorial suggestions that might help me get the ball rolling to reach my goals as well as understand what I'm doing. Version 6.11.5