Save Game - What do I need?

I know this question is asked a lot. I’ve seen numerous posts asking how to make a Save Game function and they’re always answered with “Its complicated (blah blah) no single answer (blah blah).”

What I’m asking is: what are the basic components (like Serialization, arrays, etc.) of a simple Save/Load feature?

That way, you can tell me WHAT I need and I can go learn it myself. So, please, don’t answer with “It’s complicated and it would take too long to explain” because I’ve heard it a thousand times.

Only you can answer that question. When you load the scene, what is it’s state? When you save the game, what is it’s state? Save the difference. You just have to save all possible things in the scene/game state that can be changed(level, health, object positions, time, etc. , so that you can bring your game from start state to current state when loading, or last save to now.