You get a raspberry pi. Then you get a durable SD card. You make the card bootable with the appropriate tool on your PC. While you're on the PC, you can make additional configuration changes in text files to configure wifi network credentials, static IP address and others. WIFI credentials being most important if you don't plan to connect it by ethernet or don't have extra monitors, keyboards, and mouse.
Then you place the SD card to the Pi and boot it up. It automatically connects to the WIFI using the credentials you set in the SD card. If you used an static IP address, use it to ssh into it. Then copy the pihole installation code from the pihole website. And you're done.
If you want to give pihole a try before you get a Raspberry pi, you can install it within other Linux OS, like Linux mint. You can move all the configurations by exporting them later.
What's the current record? I don't think many people outside US care enough to give this any thought at all, let alone watch it.