@wisteria27 you mentioned that you want to “major in the medical field, such as biomedical engineering”. IMO, colleges try to build a well-rounded class from individuals with “spikes”, and college apps are kind of like applying for a job. Colleges want students with a proven track record that suggests they will become leaders in their chosen field of study.
With that said, I would suggest focusing on the activities related to your major such as HOSA and leadership opportunities such as Class Office. Do these to the best of your ability and aim to place at states for HOSA and even attend/place at ILC; try to change something about your school with your position in class office and aim to continue to be Junior class president if you get selected as Sophomore class president this year. Also, don’t start a club just for the sake of putting it on your resume. If you’re busy and don’t really care about the club/ startup, it won’t have a tangible impact (e.g. feed and clothe 500 homeless around the city or raise $5000 for a cause and get featured in your local newspaper). WIthout impact you can speak to in your essays, your startup is a complete waste of your time.
Also, if you have a deep interest in bio/ bioengineering, cold email around for an internship at your local university; internships are a great way to show colleges you’re super into your major, but more importantly, they are quite fun and enlightening and help you develop as a person. As for your question about pre-IB history, I can only speak to my experience taking IB HL Econ and doing well without any previous business/econ classes or experience. These are just my 2 cents and I hope they help!