One of the most popular visual novel engines, Ren’py has straightforward language for beginners and allows more advanced users to customize their games even further with Python.
Runs on: Windows, Mac, Linux
Games playable on: Windows, Mac, Linux, Android, iOS (requires Mac)
Hover over any link for a preview!
https://www.renpy.org/doc/html/quickstart.html
https://www.youtube.com/watch?v=_-hNdKUygxE
(Documentation is best used as reference after you have already started learning!)
https://www.renpy.org/doc/html/index.html
https://www.renpy.org/doc/html/conditional.html