Sales, especially at the stage of your professional development, have nothing to do with pure and noble creativity, if you thought otherwise.
Creativity. Wildly complex activity that will require significant effort from your brain.
Imagine that you have a bag of parts weighing two and a half tons, from which you need to manually assemble a car. That's what awaits you. Do you really think you can just sit down with your muse and quickly paint a top masterpiece for the last 2,000 years and the next 5?
If you've never drawn before, it might take you several weeks to create a decent landscape, still life, or portrait. And all because you'll have to pay attention to the quality of the watercolor drawing, think about accents and lines, follow the rhythm, composition, light, and air, and maintain the viewer's interest. It's not as simple as it may seem. And if you make a mistake somewhere, it will be noticeable right away, not only to an experienced artist but to anyone who has heard of watercolor. Approach it like your favorite job.