NixOS docs themselves are a tad lax, but it will get better.
Learning nix itself is also important:
Just this morning I was having issues with a wacky dual-boot install with NixOS and Windows sharing an EFI partition, and quite interestingly ChatGPT and I were able to troubleshoot the process and get it resolved in under half and hour. I was really impressed by the specific configurations it was giving me for my /etc/nixos/configuration.nix , so that is also another resource you may consider leaning on when you run into walls in other documentation sources.
What about Traccar? I see a section in there for “drives”, although I just leave mine on all the time