It sounds like you have some ideas in your head, that you want to try and produce to get it out of your head. Every true creator can relate to this.
The naked truth is that to use Unity fully as only a tool to get to your goals (without thinking much about HOW to do stuff), you will need to know something about programming in an object-oriented programming language (C#, Java or C++, preferably C++), something about real-time simulation engines and something about Physics-systems. These are the core components in any game (some logic, some physics, and rendering an image more than 26 times per second (rendering engine) ).
I have been programming games, sims and tools since 2007, starting in C/C++ and it still took me an entire month to learn how to use Unity efficiently.
If you want to pursue a career and really quickly get into games and all the underlying stuff, I'd strongly recommend you joining the Game Institute at https://www.gameinstitute.com/. Their courses are cheap and the content is written for people who knows nothing - AND it will get you straight to the top. They even have courses in some of the game engines like Unity3D and Unreal Engine 4. Here, you will learn to code, the inner workings of a real-time sim engine, to animate, to model, and get a really good feel for most customs in the field. The tutors are energetic and know exactly what you mean most of the time. The courses are self-pased, so you can take all the time you need.
It is really bold just downloading Unity and expect to be able to create a game from nothing. Most good game developers know everything about efficiency(because the more efficient their code is, the more features and visuals and AI can run simultaneously) - so algorithms, math, Design patterns and Software architecture, and an understanding of the hardware that the programs run on is second nature to those of us who are good at it.
So, the recipe is:
1) Take some courses in programming
2) Take some courses in game engines
3) Take some courses in 3D modelling and Animation
4) Take a courses in using Unity or Unreal Engine
5) Fulfill your dream by designing a game-play and creating some concept art + simple story.
6) Implement it
7) Release and profit/get your heart out there.
I hope you chase this dream of yours - it is an incredibly illuminating journey. Feel free to contact us/me anytime if you have any other doubts or uncertainties about your direction.