You are running either Linux or macOS*, and have installed the Nix package manager using these instructions*. You do not need to install anything else, including needing to install Haskell, as Nix will manage that for you.
On a Linux system managed by systemd, its Journal feature manages the logs for everything from kernel to user level services. These logs can be accessed using the journalctl command. The particular query of interest is to retrieve kernel logs from the time before current boot.