Hi there! I am a US citizen that will be heading overseas to do my postgraduate work in the UK. It's great to hear that you're interested in US schools!
From how I understand it, the US undergrad university system works much differently than the UK undergrad system, especially with respect to our majoring process. Specifically, you can apply and enter in to a US university undeclared, which means you haven't decided on your major yet. My roommate in undergrad was an international student from Shanghai, and she was undeclared for two years until she decided to major in accounting. Similarly, I entered into my university majoring in psychology and then added a second major (biology) during my sophomore year. The undeclared pathway exists to allow students to explore potential subjects while obtaining the general credits you'll need to graduate without putting off university altogether. This also enables students who are concerned about obtaining admission to a competitive program to instead apply undeclared (which can generally be less competitive) and then declare their intended major sometime after their first semester. Based on what you've described, it actually sounds like this might be a great option for you.
I will say that international admissions to the US aren't great right now due to the current government situation, but if you manage to pull through with decent grades and a good SAT/ACT score, I think you shouldn't sell yourself short. You can (and should) also try to find an advisor that has familiarity with the US undergrad system and applications process. Good luck to you! Feel free to reach out if you have other questions.