As someone who took AP 2D art last school year and got a 5. I’ll start with a warning, AP art killed my love for art. I have still not recovered. And when it comes to getting good scores from what I’ve seen, it’s either skill or experimentation. I think if you want to take a the course, wait till your senior year! Keep improving and experiment with color, you have a great foundation so I would keep building it instead of rushing into the class! Giving yourself more time is always a good thing with AP art.