When starting out, you may notice different charters using different editors, and get confused as to which one you should use. There's 2 main editors everyone uses, DdreamStudio and Arrow Vortex. I'll explain some basic information about what each is best at on this page, however if you want a more comprehensive guide, check out the official Etterna wiki page, here!. It only covers Arrow Vortex, though!
As for when you're starting out. I would recommend you use Arrow Vortex! Ddream is a very old and outdated software, with numerous bugs, and is mostly only used by older charters who have gained reflexes with it. Arrow Vortex is significantly more user friendly and especially better for new users. It also has more resources to learn from, such as the aformentioned wiki page.
You can find arrow vortex on the official site, here!. The page has some information about the program too on it, so you might want to look around.