@tant
I am going to be very blunt now:
The story is the main source of inspiration and given we all use the same engine and models, it's the one thing that makes games really different from each other.
If you can't come up with a story on your own you miss a basic prerequisite for being a game developer.
But apart from that, why not giving it a little cheaper?
Think of ONE game situtation you would like to create, play yourself and show us.
Think of a SINGLE level (consisting of only a few rooms) to use for this.
THIS is going to be challenging enough for a start and if you accomplish this, then you're allready above the average newcomer.
Good Luck!
In case you find my grammar and spelling weird ---> native German speaker ^^