The game engine usually used for visual novels (like this one) is Ren'Py. It's relatively easier to get into and is free. It can be found at https://www.renpy.org/. It's also got a Discord server and other online forums where you can ask for help and chat to other game developers using Ren'Py!
There's also RPG Maker which I think has some free version but also a paid version. It's usually used for, well, making RPG games but I've also seen it used for visual novels with places you can walk around in as well.
And if you want to get really advanced there's also game engines like Unity and Unreal which are very versatile but, as a result of that, are also a lot more complicated.