This was posted before in the College Admissions section at https://talk.collegeconfidential.com/college-admissions/1995563-faq-high-school-college-prep-base-curriculum.html , but it looks like the questions about high school course selection are mostly here, so it may be more helpful here, with some additional information.
High school students aiming at highly selective colleges should consider meeting the following base curriculum that is commonly expected. Of course, additional academic electives beyond the base curriculum are fine and expected to fill in free elective space in the schedule.
- **English**: 4 years.
- **Math**: At least to precalculus. Students who complete precalculus in 11th grade or earlier should take calculus if available. Statistics should be considered an additional elective, not a substitute for precalculus or calculus. *Note:* not completing precalculus in high school may result in needing to take it as a remedial course in college. Not taking calculus if available after completing precalculus in 11th grade or earlier may make a student less competitive at a highly selective college where most applicants have taken calculus. A small number of colleges explicitly state that calculus is required or expected: https://talk.collegeconfidential.com/college-admissions/2015601-what-us-universities-explicitly-state-that-calculus-is-required-or-expected-for-frosh-applicants-p2.html .
- **History and social studies**: 4 years generally preferred.
- **Science**: 4 years including a year each of biology, chemistry, and physics. If only 3 years are taken, it is best to include a year each of biology, chemistry, and physics. *Note:* many colleges' frosh-level courses in these subjects list the high school course as a prerequisite, so prospective science majors, engineering majors, and pre-medical students in college should be sure to include all three.
- **Foreign language**: Completion of level 4 (4th year) of high school language or equivalent generally preferred; having only level 2 or lower is likely to be significantly disadvantageous. *Note:* many colleges have foreign language graduation requirements; completing a higher level in high school may allow fulfilling the college foreign language graduation requirement in fewer (or no) courses, allowing more elective space in college. See https://talk.collegeconfidential.com/college-admissions/1802227-faq-foreign-language.html for additional information.
- **Art or music**: 1 year. *Note:* not listed by many colleges, but sometimes a surprise for high school seniors considering a college that does list it.
- **Academic electives**: Select according to interest to fill free elective schedule space.
High school students aiming at less selective colleges may not need to complete as many or as high level courses as listed above for admission purposes. However, completing the pattern suggested above will prepare the student for college better than if the student only takes the minimum required high school base curriculum for the less selective college. See the notes above.