Using an installation iso provided from https://endeavouros.com/, you can flash the iso to a USB stick (using Rufus or Balena Etcher) and power off the computer.
After powered off, power the computer on while spamming the BIOS key, and look for a setting called "Secure Boot". Disable this for now.
After secure boot is disabled, plug in your USB and reboot. It should boot to a small menu with options. Select the first with "Enter". Wait for a bit.
Now, a familiar desktop GUI should appear. Continue with the installer process, selecting LXQT as the desktop environment for maximum performance.