Renpy is super easy for doing a basic image + dialogue style VN or KN. There's the possibility of doing much more like semi animated characters, minigames, inventory+shop systems etc, but that is where is gets complex. If you keep your game design and scope simple for your first project it should be fairly simple - most of the effort will go to getting the artwork organised and writing a competent sexy story.
Renpy official documentation is not helpful for a new learner, it's mainly written from the developer point of view / assumes lots of knowledge about how it all fits together.
For a super simple intro to the basic VN syntax, read through the script for "The Question" sample game included in the package.
Beyond that, Thundorn's youtube channel is pretty good.
"Ren'Py from beginner to advanced"
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He's also got a "Renpy let's code" series that takes you through creation of a whole game.