UNREAL games dev - how much coding knowledge

Hello

I am teaching a group of students the fundamentals of programming in C++. How much hands on coding is required for developing for example, a space invaders style game? I am from a programming background, but totally new to UNREAL and game dev in general? Does UNREAL produce all the code necessary for a given game on the fly or just the bare bones?

Apologies for newbie style questions.

C