The reference to ‘OctoPrint’ was in LulzBot’s documentation. You don’t actually need it. What they really want you to do is open a Console / Terminal window to type those commands.
OctoPrint is a network print server and most of the time people run it on a tiny little Raspberry Pi single-board computer (it’s a tiny low-cost computer roughly the size of a deck of playing cards). The idea is that instead of connecting your expensive computer to the printer … you connect the cheap Raspberry Pi (OctoPrint) server to the printer and Cura (which has an OctoPrint plug-in installed) knows how to send your print jobs across the network to OctoPrint and OctoPrint takes care of spooling the job to the printer for you. Check out: https://octoprint.org/ “OctoPrint” is the server software, but a Raspberry Pi needs an operating system (it runs on a microSD card) so they have this pre-built OS image called “OctoPi” … and if you copy that image to the microSD card, it has everything necessary pre-installed. The first time it boots it asks a few questions, but once configured it becomes your print-server.
BUT… OctoPrint’s user interface runs in a web-browser (you don’t actually connect a screen, mouse, keyboard, etc.) and it has a “Terminal” tab that lets you type direct Marlin G-Code commands to the printer and see it’s responses. You can do the same thing in Cura (no OctoPrint needed). In Cura, there’s a “Prepare” side … where you get a job ready to print, and a “Monitor” side where you watch the job in progress. In the “Monitor” side, there’s a “Console” button. This opens the interactive terminal where you can type in the Marlin G-code commands.
Your printer speaks a language called “G-Codes” (because most of them start with the letter G. You can find the full documentation here: https://marlinfw.org/meta/gcode/
I wrote a primer on the topic that you can find here: Demystifying G-codes & Why you might care
When you bring a part into Cura and have it generate a “g-code” file… it’s a list of human-readable text full of those commands. It tells the print head where to move and how fast, how to heat up, etc. Literally everything the printer does is based on those codes.
It turns out the printer has some non-volatile memory so configuration changes like z-axis offsets, etc. are all stored via g-code commands. Printers that have a display (like the Mini 2) would also let you do this via the display on the printer (no terminal needed …it has menus). But the Mini 1 can only be controlled via a computer.