How great to have a number of choices and I can see why you would want to do them all! My advice would be to study hard when you are not training, if only to give yourself the best chance of getting into medical school. If you go down the route of becoming a professional athlete, your studies will hold you in good stead, because you will need to have your wits about you to make sure your PR people are doing the right thing, your Accountant is making the best decisions for you, and you will most likely need to do some form of public speaking and you will want to sound informed and articulate.
With regard to becoming famous, we have a saying in PR, and that is, don't do anything unless you are prepared for it to be on the front page of the newspaper. To ensure being famous happens for the right reasons, make sure that how you conduct yourself on social media, your overall online presence, is all positive and reflects the brand and image you want to create for yourself. Many careers have been cut short, and sponsors have ditched their clients, because a journalist has dug up dodgy internet content from years ago.
I hope this helps. The right coach and mentor will also be able to support and guide you along your journey. Seek these people out, if you haven't already and be clear in your ask as to how they may be able to guide and support you. Best of luck!