There are lots of spooky books for children! Some kids love that kind of thing. You can show a lot of fear and tension without ever showing blood. Your art reminds me of a game I enjoy called Don't Starve. The artwork has scratchy line work that gives the game a more spooky ambiance. Take a look at the way the artist uses line and muted color to give the story it's spooky feel without showing blood or gore.
Above all, just draw what you love. The market will find you as long as you share your work openly.