@theprairiefox Colors can be tough to figure out! There are so many tips and theories. But you can do it! Here's a couple of ideas:
You could use a limited palette to start out, like 3 colors, and use only dark/light tones from these.
One trick is to have your focal point in warm colors and the majority of the rest of the scene in cool colors, or vice versa. This helps draw attention to your focus.
It can also help to choose one main overall color, then paint over it at 70-80% opacity. Or layer it over your other colors at 20%. That way all your colors will share a similar hue, and feel like it's all part of the same scene.