Well i don’t know what you bought but the Unreal Engine is free to use & learn on with plenty of free content to use at the Epic Marketplace, you should not have to pay for anything till you actually make money selling content, that being said, Yes the Unreal engine is by no means easy to master, the learning curb is steep & you need to know at least a little about coding, rendering, animation, photography because it’s all about the right lighting & environment effects and knowing how to use cameras with different light sources & angles for shooting the right perspective in scenes or gameplay.
It would be handy if you know physics & advanced mathematics because you’ll need to vector in velocity & understand concepts of gravity & weight/mass to develop truly great blueprints for models & simulations.
You need to know a fair bit about coding when writing widgets for blueprints & connecting up things like animations too game functions like picking up an item and having the character use it some way in the perspective you want 1st or 3rd person.
Creating good games isn’t easy so you can understand why it can take AAA companies upto 10 years to complete a masterpiece like Skyrim or Fallout.
The editor has so much to offer it’s not easy to learn quickly even if you have some experience in computing or using other programs which may have similar functions.
Too truly make an game you need a hell of a lot of skill in many programs including audio so you’re skill set in the music business would help greatly in those areas of products…
It’s probably best if you can find others in you’re local area to help you develop & learn the editor because there is so much too know.
I find Youtube helps me learn many functions & how to use the editor but i would love like a prima guide reference book for the Unreal editor particularly for version 5 that would explain in segments how to use functions, even if they do change with updates over time a hard copy book version explaining the many functions the Unreal editor has would be a great help to new people trying to learn such a complex editor.
One thing i suggest if you’re lacking a particular function in UE is look at the list of plugin’s that will help you develop, everything from bridges to other editors or more tools for modifying static meshes or landscapes, stuff for sculpting meshes & item creations too painting & texturing.
You can download many shaders free, the Megascans shaders are a highly detailed set of textures that cover heaps of environments, you can easily apply decals on anything so you don’t need programs like substance painter or photoshop when using UE.
UE5 has so many functions that even if it doesn’t have one you need you just can create plugins to things that do then export needed stuff into UE.