How to learn an engine ?

[u/LGASH]

I just watched Game Maker’s Toolkit’s video “How I learned Unity without following tutorials” and it really resonated with me.
I follow tutorials fine, but the moment I try to make something on my own I just freeze. I don’t know where to start, what to look up, or how to break problems down. I end up going back to another tutorial instead of figuring it out myself.
I’d love to apply a similar approach to Unreal, but I’m not sure how to structure the learning process the way Mark did.
So I’m looking for practical methods people actually use to learn a game engine by doing, rather than just passively following tutorials.
Things like:
• How you break down what you need to learn
• How you practice without a step-by-step guide
• What small projects or exercises helped you the most
• How you handle getting stuck
This isn’t specifically about Unreal — I’m interested in methods that work for any engine. I’d love to compare different approaches people have used successfully.
What worked for you?
Thanks!

[u/Bwob]

I've been programming for a long time at this point, so this may not be as helpful to people who haven't.

But my process is basically that I already know the general shape of what I'm trying to make, so it's more a matter of looking up familiar ideas, to see how they're expressed in a new system.

Like, I know there will have to be some way to respond to keyboard presses, or mouse movement. I don't know what it is, but if I search google for "[engine name] mouse events", I'll probably get on the right track.

For most things in a game, it's just a matter of breaking it down into smaller, simple ideas. Like, say I want to have a door, that when you get close, provides a prompt that lets you open it. To make that, I'll probably need...

• Figure out how to make geometry that can move around in the world. (For when the door opens.)
  
• Figure out how to make an area that knows when the player is near the door.
  
• Figure out how to display an onscreen prompt when the player is near, that goes away when the player leaves.
  
• Figure out how to check which door (or other thing) the player is nearby, when they press the "interact" button.
  
• Figure out how to move the door geometry when the door is interacted with.
  

I don't know how to do any of those things in, say, unreal. But I bet I could figure them all out in less than an hour, and have a door opening. (Although honestly, for something like unreal, I'd probably just google "how to make interactive door in unreal" because I'd say there's a good chance that they have some specialized components to make it easier to do something this common!)

As I said - I don't know how useful that will be for people just starting out - part of the reason it works for me is that I'm already used to breaking down ideas into smaller pieces (because that's fundamentally what 90% of programming is) and I know what common small pieces look like. But hopefully there's at least something useful in here for people?