First endeavors are supposed to suck. The first time I got behind the wheel of a car, my father gave up on me when I slammed on the breaks and almost put him through the windshield while my two younger brothers rolled around in the backseat laughing their heads off. I ended up being taught to drive by my unflappable grandfather and a classroom instructor. There is a reason they require you to practice driving before they give you a driver's license to drive on your own.
Just like with driving, you have to put in practice time to get good at writing. Don't get discouraged if your first attempts leave your siblings laughing. Maybe you were meant to write comedy.