You don't even need to write a single code line for the thing to work, if you just want the given features. Practically speaking, the engine create a "default game" that you customize with different data (items, variables) so you don't need to touch functions.
There's a meta-language that allow you to create events and cutscenes, but is mostly like plain english and very easy, with even buttons for macro (like move this, open that, play this and so on).
THEN, if you want for your game to act differently than default, you can use the plugin system and create snippets that change the core functions so they act differently - there are a BILLION of ready made plugins, so you probably don't even need to code the same.
BUT if you actually want to do something unique, special and very very very PRO, you can try to code some plugin on your own and learn both JavaScript and how the engine core work, but probably this is very far from your actual needs.
FEEDBACK:
It work fine if your goal is to produce a default JRPG - to make something even slightly different things become abruptly much harder. You'll need a plugin for even the slightest change in the behaviour - and if that plugin doesn't exist the curve become steep to an uncanny degree.
As long as you stay in the borders of a JRPG and use default resources, this engine work like a charm, is relaxing to use and help you focus more on the plot area than boring stuff like mapping or set a database.
It could be very fun and immediate for a kid to produce a game, but is not ideal to introduce someone to coding logic (this engine do the impossible to keep you away from coding...).
