please help me!
Don't worry too much about what you want to do in the future, or what you might study at A level even. You will change your mind about these things a million times before you start applying even for college or 6th form. Choose subjects that keep your options open, and that you enjoy. For example, if you're good (getting level 7s or predicted 7s) at science, then I would personally say it's a good idea to choose Triple Science, else choose Double. I would recommend choosing one of History or Geography, and also choose a foreign language if it's available to you.
:d i wanted to be a pharmacist when i was in year 9, found out that ideas change drastically in the next 2 years. Just choose the subjects you enjoy it will make no difference to been a pharmacist as its mainly chemistry and biology (science).