If you want to get your Raspberry Pi up and running Lynx quickly, the Lynx CI ISO is for you. Simply download the LynxCI ISO from here and then flash it to an SD card. We have found Raspberry Pi Imager very easy to use. Use the option "Use Custom," then select this file. When done, insert the card into the SD card slot on the bottom of the Raspberry Pi 4 and power it on. No keyboard, mouse, or monitor is required. You must plug in an ethernet cable to the device (you can set up wifi later if you like). A Pi 4 will be fully functional in about 20 minutes (it will take about 4x longer on a Pi 3).
Here is an article that explains the whole process.