You're afraid because you're thinking about the end, not about what you're doing.
It's not what you paint. It's how you paint it. You don't have to paint elaborate things. Paint simple things as beautifully as you can.
If it's all wrong, it's all right.
You can't get it right, until you make it wrong.
I don't look where I'm going, I look where I've been.
It is in the contrast of light and dark that design happens.