Is not so hard:
Easy way: use the gitea interface You will not yet get all what git is about, but you can make a new file, save it with the right name and .md extension, copy your part of the text, edit it and save it.
use GIT This means two things: first you will have git on your machine. Is a multiplatform software that works on terminal. Because terminal is easy Because terminal is the same on any machine you can enter into from remote, real or virtual. GUI’s tend to be different, terminal are the same. If you learn something on a gui you have to learn it again in a couple years. With terminal you are more or less set.
so what is GIT?