I admire your asking! Deciding on a career is a scary decision to make. Fortunately, as others have advised, what you need to do now is to not pursue anything single-mindedly. At this point, you have little idea what it means to work as an artist, musician, or as a biologist/biological technician. For one thing, it is a very rare job that doesn’t include a fair bit of paperwork, tedium, putting up with some annoying people, and having to do stuff you don’t enjoy. Sometimes this can lessen a person’s original love, and they regret making their passion their work. For others, that doesn’t matter, as long as they get to do enough of the fun stuff. There are also some combination professions possible, such as scientific illustration.
Most sadly, there is often so much competition in your currently preferred fields that finding a job, or earning sufficient money to live on, isn’t realistic unless you’re lucky, or exceptionally good, or both. There is a world of difference in being a very decent amateur, and being professional grade. In that case, you may need to look for a different path, while doing what you love in your spare time. Outside interests are wonderful to have.
Circumstances can change your trajectory, too. I thought when I was young that one decided what one liked, got trained to do it, and that was that. I already knew I wanted to study insects when I was five or six. However, I realized while doing my honours undergrad project that I didn’t enjoy fieldwork enough to go for a graduate degree or to be an academic. I did rear bumblebees for four years. That was by turns both interesting, and sheer drudgery. Then the business moved from Canada to the USA, and nothing entomological was available locally. Because I was a volunteer blood donor caller, I ended up with Canadian Blood Services. I worked at blood donor clinics and booking platelet donors for 25 years, until I retired. It was, by and large, satisfying. Not what I thought I’d be doing when I was six or sixteen!
My love of nature certainly never vanished. Watching insects while gardening, hiking, reading, watching nature documentaries and visiting museums filled the gap. Plus, since discovering iNaturalist, I have found I can still contribute to entomological knowledge.
So, keep your options for now. Take an open-ended selection of high school courses that will qualify you for university entrance, but see what extra-curriculars are available, and lessons and courses you can take in arts and music. Is there a local high school that is known for their arts and music or academic programs? The right teachers can make a huge difference! Outside of that, volunteer, look for appropriate summer jobs, and talk with all sorts of people about their work, and how they got into it. Oh, and save this column! In 25 years, it will probably be fascinating for you to compare what you are being told now with what turns your life takes. It might even be something to show your children, if you have any.