Soon or late in his career (sooner than late) any DM will try his own adventures.
To run a game based upon his own ideas is without doubt one of the biggest feelings of DMing.
Alas, things ain't easy.
Many hours of work can be ruined in a second by a clever players' ideas (at best) or by disruptive players (at worst).
Don't worry; it happens to any DM who doesn't know this fundamental
Law of adventures of the Good DM
Every time you write an adventure, you write 3: the one you had in mind, the one you actually have written, the one your players will play
It does mean it's useless to detail everything in your adventure and you can't forecast every party's move.
So don't waste your time writing down things you won't use.
Put down only essential data ( such as traps or secret doors in a dungeon room) and be focused on your real goal, which you may find in the following
Good DM Quote #1
The real task when writing an adventure is to create anything brand new but tuned to what players want.
You'll see how to reach your goal in the following posts.