Hi, I started working on my 1st (2D) RPG (using C++ and SFML). In the past, I've only worked on platformers or what I call fixed-view (i.e. Asteroids, Pac-man, Pong). I'm wondering how you integrate quests, characters, etc. into the game? So far the best idea I've come up with is to have a directory for quests and keep all quests or quest lines in separate files.

Maybe a .xml file that would contain a tree of quests that could refer to other quests like

<questline name="L1">
    <quest name="Q1">
        ...
        <unlock>L1:Q2</unlock>
    </quest>
    <quest name="Q2">
...

But what about the NPCs? I want them to be there whether the quest is active or not, I want quests to have the ability to kill them, change their location, dialogues etc. Basically, I want the implementation to be as flexible as possible so I don't cock-block myself later. Any input would be appreciated (ideas, projects on GitHub I could snoop on, books that aren't too expensive, anything really...)

In pac-man the ghosts all spawned in the center and asteroids was all random generation. I had a wave system that increased the number of asteroids that could be on screen at the same time, and they spawned in a random location, with random velocity.

I have no experience "scripting" a game and the reason I'm asking is because I don't know where to start. I'm all about learning from my own mistakes, but I'm sure some inspiration can't hurt.