A story writing template based off of Dan Wells's "7 Point Plot Structure" I suggest clicking on the attached link for a video series Dan created explaining the 7 Point Plot Structure in great depth, using a number of different examples. It's an extremely educational and entertaining lecture. (Click on the attached link for more in depth information)
Read notes for further details about the 7 Points. (uses Harry Potter and the Sorcerer's Stone for examples) The Main Plot should be the main plot line that drives your story. The "meat and potatoes" of the story, so to speak.
start main character (MC) in opposite state as the ending. (IE- ends up as a powerful wizard, starts off as an orphan living under the stairs)
Plot turn 1- introduce the conflict. MC meets new people or discovers a secret. (Harry learns he is a wizard!)
Pinch 1- something goes wrong. Villain is introduced, MC is forced to act. (A troll attacks)
Midpoint- character moves from reaction to action. (Harry finally learns the truth about Voldemort and the Sorcerer’s Stone, and swears to protect it)
Pinch 2- situation becomes hopeless. The Jaws of Defeat. The death of a mentor, a plan fails, the bad guy seems to win. (Ron and Hermione fall to traps in the dungeon, and Harry is left to face Voldemort alone.)
Plot turn 2- MC obtains the vital piece of info/courage/item he needs to vanquish bad guy. (Harry finds the stone in his pocket, and learns that the power to defeat Voldemort is in him- by touching Quirrel.)
MC succeeds, and is now a changed person. (Harry defeats Voldemort, has friends and cool new powers.)
Look at the ending from the beginning
Where do you want your character to end up?
Turn your attention back to the beginning
Put the character in a position where he has to change to reach the goal waiting for him at the Resolution.
This is the point where the character moves from reaction to action.
Instead of "reacting" to a situation in his life, he instead makes the decision to "act" consciously change it.
If your story has a sub plot that runs alongside the main plot, make notes for it here.