I got started with just a laptop with a built-in mic, and Audacity (free software). Just recording the sound in the room
Then I got a 2x2 USB interface, Presonus Audiobox, but there are a bunch with similar features. I use a Roland microcube with a bunch of amp models and built-in effects, but don't use much of that capability. I mic the amp into the audio interface. While recording I monitor with headphones. Actually I usually monitor the backing track or click track in one ear while hearing the room in the other. Still using Audacity software.
Other folks here use amps that have a direct USB output so no mic needed.
How difficult? Well there is a learning curve. There is a recording topic in the forum way down toward the bottom.
Probably the most difficult thing is not going all "deer in the headlights" when you hit the Record button
And I have sent innumerable takes to the bit bucket before posting one I was happy with. That's how you find out what you need to work on. For "lesson" material, with very rare exceptions I make myself record the whole thing in a take, not splice together bits and pieces from various takes.