How reasonable is going to UK from US?

I am a High School student looking at possibilities. I love the idea of learning in England but I can not find much good information on it giving direct answers. Let us say I have a good shot at a school like Lehigh and want to go for a degree in chemistry. What kind of university could I get into? I realize it is not a 1:1 comparison but an idea would be helpful. What kind of financial assistance could I get going overseas? Would I be incapable of going to even a cheaper school because of lack of aid? And if I am will I be putting myself at a disadvantage with going for a degree there and going back to the US?

Thank you to anyone who can give me insight into these issues.

Have you checked the individual universities’ websites for admission and aid information? The wording is a bit different than here in the US. Remember that you are looking for international admissions. It took me about two minutes to find admission requirements and financial aid information for US undergrads applying to Cambridge University:
https://www.undergraduate.study.cam.ac.uk/usa
https://www.undergraduate.study.cam.ac.uk/international-students/financial-support
https://www.cambridgestudents.cam.ac.uk/fees-and-funding/funding/student-loans/us-loans

Some universities in the UK participate in the federal student loan program, but that will be pretty much it for financial aid. Job placement will also be a challenge as the universities do not have the same kind of contacts in the US job market as a US college/university would, and name recognition can be a challenge. The usual advice is that a student like you study in the US, and do a semester or year abroad in the UK.