Generally speaking I think that a student’s major should be a compromise between what you like, what you are good at, and what can help you to develop a career. There is a lot to consider here, and this does take time to figure out. There are some majors such as mathematics or biology which can apply to a number of possible careers, but which do not necessarily point to any one specific career. Thus a student can graduate with a bachelor’s degree in for example biology and still not have decided what they will do with their career. We each figure it out over time.
Your extracurricular activities do not need to have anything to do with your major.
It is very common for students to change their major after they get to university. As two examples, both daughters changed their major after starting university. Similarly I did not even pick a major until the end of my freshman year. This is normal (some schools require you to pick a major before you start, some do not, some do not even allow you to pick a major until the end of freshman year or beginning of sophomore year).
In some schools you need to apply to change your major. If you are trying to change into a few specialized majors such as engineering or computer science at some schools, or if your grades are bad, this might be an issue in some cases. In most cases that I am familiar with this was not a problem at all. The student might have needed to apply to change major, but the application was in most cases accepted quickly and easily.
This is a good place to start. You start with a major that you are interested in, take a few classes in a few different subjects, and see how it comes out over time.
I also agree that chemistry is a major that seems to be closely related to pharmacy. I know someone for example who was a biology major working in a lab, at a company where they were trying to find a drug that would take out a particular hormone in order to help treat a particular disease. They had chemists or biochemists who would figure out which specific drugs seemed likely to take out the hormone, and biologists who would then run tests with human cells and see whether the hormone was impacted by the drug, and also whether anything unfortunate seemed to be happening at the same time (such as cells dying). Certainly organic chemists were needed to keep this research going in an attempt to develop useful and valuable drugs.
You probably should just apply for the major that you find most interesting, and see how it goes over time. Again, do not be concerned about whether any ECs fit your intended major – in most cases there does not need to be a fit between ECs and major.