If you can read C++, this one is surprisingly easy to get into. You can do most things with the amazing graphical editor and for the very few cases where that isn't powerful enough, you can debug the whole thing in Visual Studio which means you can see parameters and stack traces for everything. And in my personal opinion, classes are predictably named and layered in an useful way.
I found learning it and working with it quite enjoyable, especially compared to my experience with Unity where the lack of source code forced some very ugly workarounds on us. And with "only" low millions in annual revenue, Unity wasn't even willing to discuss the price for source code access... but with UE, you get a triple A game as demo project for free.
I use unreal professionally. I would say that unreal is very opinionated in the way things are done. This is a good thing if you can stick to it and know how to leverage the systems in the way they were intended but makes it also makes it incredibly easy to shoot yourself in the foot by not adhering to the (sometimes unwritten) rules.
My wife and I started learning game development a year ago after 15-ish years in the software industry. UE is one of our main drivers. It is probably the hardest to learn when compared to Unity or Godot, but you also have some insane capabilities. Taking Godot detours definitely helped our understanding of how games work, and we should have embraced blueprints a lot more instead of trying to solve everything in C++.
TL;DR: yes, it's possible, but it has a learning curve.
Doing software on the side was quite common for 15 year olds during the 8 and 16 bit revolution, many well known game developers in UK started exactly at that age.
It depends on your background. Learning C++ is a prerequisite to being efficient in Unreal. If you already know C++ it can be done without too much hassle. If you also understand the basic principles of game development picking up UE is a breeze.
I found learning it and working with it quite enjoyable, especially compared to my experience with Unity where the lack of source code forced some very ugly workarounds on us. And with "only" low millions in annual revenue, Unity wasn't even willing to discuss the price for source code access... but with UE, you get a triple A game as demo project for free.