Some good answers above.
The key thing is not to expect too much as an absolute beginner - it takes time to develop an understanding of the high level approach to building a game in Unreal (or any engine), and then further time to understand the lower level tools and techniques available to achieve specific elements of the game.
Once you have that understanding, you can think more seriously about long term projects that you may actually release. You’ll know when youre starting to get to that point because you’ll have ideas for things, but incorporated into those ideas will be notions of HOW you will try to do it rather than just “it would be cool if…” type things. What data do I need to create or to get, what format does it need to be (float, integer, vector and so on), what does it represent and what do I want to do with it so that the end result is the gameplay feature I had in mind.
The best way to get to that point, is to jump in with some basic Blueprint tutorials. I mean really basic, like “here is how to switch a light on and off in game” or the like. They will introduce you to core concepts, and the more you do the more you will understand about how you make arbitrary game objects and actors behave in a specific way. Before you know it, you’ll be ready to tackle more advanced tutorials that assume a bit more pre-existing understanding of how the engine works in general, and completing those will further advance you.
As mentioned already, Unreal is not an asset creation software in the sense you asked about. There are assets you can acquire from the marketplace, and from places like Megascans, but beyond that you will need to get familiar with external packages to create specific visuals. I would recommend doing so alongside learning the engine; even if you have no intention or capacity to become a professional grade artist, there are a lot of workflow benefits to being familiar with those applications. Even if you work with an artist at some point, you’ll want to be able to adjust the content they created in many cases, and a basic understanding of something like Blender is not too hard to gain.
That said, it is a separate discipline all its own at the higher level. I have been doing 3D art for nigh on 20 years, 10 of those in a professional studio setting, and I still learn new tricks all the time. I very much doubt I will ever be done learning, truthfully.
All in all, even making even a simple game is a complex, multi-faceted endeavour - and it only gets more so as the game you want to make gets more complicated. Don’t worry about building an entire house without first learning to dig and pour the foundation, so to speak.
As HAF-Blade said, get stuck in and HAVE FUN! It is, deep down, a very rewarding creative process for the most part and because of that, the complexity of it should not put you off - you will have a good time whether you release a game in a year or not.
A thousand mile journey always begins with a single step!