Hi liamsproblems,
The screens you posted are indicating that a mouse or trackpad are not connected to your Mac. The images are attempting to demonstrate how to power on a Bluetooth mouse or trackpad manufactured by Apple.
It appears that your Mac does not detect the built-in keyboard or trackpad on your MacBook Air. For now, connect a mouse to your Mac, then follow the instructions here to reinstall macOS: How to reinstall macOS - Apple Support