You need to think about these things when planning a story...
- The Plot - What happens in your story.
- The Characters - Who are the characters in your story.
- The Setting - Where is your story set.
- The 5 W's (What, where, when, why, who) - What happens, where is it set, when is it set, why are they there, who is there.
The main and Simple things you need to include in your PLOT.
- Beginning - What happens in the beginning.
- Build-Up - Something Happens.
- Problem - Something Bad happens or something goes wrong.
- Resolution - Solving the problem.
- End - A good ending.
I hope this helped you and that you think about these things when writing.