Cannot get X11 server to work on fresh install

Okay, I did nix-env -e '.*' which uninstalled the nvidia package from above and pciutils which I had also installed using that method. I will remember to never do that again, thank you for the tip!

I tried setting that hardware.nvidia.package with no luck. Then I downgraded my linux packages to 5.15, also no luck. Then I tried setting my display manager to lightdm and also no luck. Here is my configuration.nix now:

# Edit this configuration file to define what should be installed on
# your system.  Help is available in the configuration.nix(5) man page
# and in the NixOS manual (accessible by running ‘nixos-help’).

{ config, pkgs, ... }:

{
  imports =
    [ # Include the results of the hardware scan.
      ./hardware-configuration.nix
    ];

  # Use the systemd-boot EFI boot loader.
  boot.loader.systemd-boot.enable = true;
  boot.loader.efi.canTouchEfiVariables = true;

  boot.kernelPackages = pkgs.linuxPackages_5_15;

  networking.hostName = "fins-thinkpad"; # Define your hostname.
  
  # Pick only one of the below networking options.
  # networking.wireless.enable = true;  # Enables wireless support via wpa_supplicant.
  networking.networkmanager.enable = true;  # Easiest to use and most distros use this by default.

  # Set your time zone.
  time.timeZone = "America/Denver";

  # Configure network proxy if necessary
  # networking.proxy.default = "http://user:password@proxy:port/";
  # networking.proxy.noProxy = "127.0.0.1,localhost,internal.domain";

  # Select internationalisation properties.
  # i18n.defaultLocale = "en_US.UTF-8";
  # console = {
  #   font = "Lat2-Terminus16";
  #   keyMap = "us";
  #   useXkbConfig = true; # use xkbOptions in tty.
  # };

  # Nvidia drivers unfree
  nixpkgs.config.allowUnfree = true;

  # Enable the X11 windowing system.
  services.xserver.enable = true;


  # Enable the Plasma 5 Desktop Environment.
  services.xserver.displayManager.lightdm.enable = true;
  services.xserver.desktopManager.plasma5.enable = true;
  services.xserver.videoDrivers = [ "nvidia" ];
  hardware.opengl.enable = true;
  hardware.nvidia.package = pkgs.linuxKernel.packages.linux_5_15.nvidia_x11;

  # Configure keymap in X11
  # services.xserver.layout = "us";
  # services.xserver.xkbOptions = {
  #   "eurosign:e";
  #   "caps:escape" # map caps to escape.
  # };

  # Enable CUPS to print documents.
  # services.printing.enable = true;

  # Enable sound.
  # sound.enable = true;
  # hardware.pulseaudio.enable = true;

  # Enable touchpad support (enabled default in most desktopManager).
  # services.xserver.libinput.enable = true;

  # Define a user account. Don't forget to set a password with ‘passwd’.
  users.users.finley = {
    isNormalUser = true;
    extraGroups = [ "wheel" ]; # Enable ‘sudo’ for the user.
  };

  # List packages installed in system profile. To search, run:
  # $ nix search wget
  environment.systemPackages = with pkgs; [
    vim # Do not forget to add an editor to edit configuration.nix! The Nano editor is also installed by default.
    wget
    firefox
    pciutils
  ];

  # Some programs need SUID wrappers, can be configured further or are
  # started in user sessions.
  # programs.mtr.enable = true;
  # programs.gnupg.agent = {
  #   enable = true;
  #   enableSSHSupport = true;
  # };

  # List services that you want to enable:

  # Enable the OpenSSH daemon.
  # services.openssh.enable = true;

  # Open ports in the firewall.
  # networking.firewall.allowedTCPPorts = [ ... ];
  # networking.firewall.allowedUDPPorts = [ ... ];
  # Or disable the firewall altogether.
  # networking.firewall.enable = false;

  # This value determines the NixOS release from which the default
  # settings for stateful data, like file locations and database versions
  # on your system were taken. It‘s perfectly fine and recommended to leave
  # this value at the release version of the first install of this system.
  # Before changing this value read the documentation for this option
  # (e.g. man configuration.nix or on https://nixos.org/nixos/options.html).
  system.stateVersion = "22.05"; # Did you read the comment?

}

I’m so new to this that I think I may be missing a very simple step somewhere. Based on this configuration, would you expect the desktop environment to come up automatically? Or do I need to run startx or something? After changing my DM to lightdm, the display-manager.service logs are only 4 lines ending with kbuildsycoca5 running....

Should I try switching to unstable and seeing what happens? And if I do switch to unstable, should I remove some lines from my configuration.nix?