Ren'py uses Python (which is an easy to learn language), and has a lot of built-in functions that are specifically geared towards visual novels - text boxes, character portraits, that sort of thing. You can find a pretty good quick-start tutorial here. Ren'py is 100% free.

Gamemaker Studio is a very beginner-friendly (while still very powerful) option; it allows for a much wider range of projects (as it isn't geared towards one specific genre, like Ren'py). It's "free"; it uses a subscription model, but there's a free "demo" version that (unless something has changed) you can use forever; the only substantial limitation is that you can't compile a final game build with it... if you get to the point where you have something that's finished and ready to publish, you can subscribe for 1 month to their premium license, compile your game, and cancel it. It has options for actual programming, or a "drag and drop" interface, where you're basically building your game logic using ready-made "blocks" that you input data into to tell the engine what to do. It's pretty intuitive and a good place to start. There's a wide range of tutorials here.