You can usually begin studies at a community college--sometimes referred to as a "junior college"; these are 2-yr colleges which offer a mix of vocational/technical certifications (non-academic training for jobs, such as auto body work, etc.), terminal degrees in some areas, or minor academic degrees (the associate's degrees)--basically whenever. They exist to educate their communities, and the "application" process is usually [i]pro forma[/i] and designed to cast a wide net/include people.

I took "adult extension" courses in 6th or 7th grade. Winter of my junior yr in high school, I took the first semester of calculus, and finished my senior year of high school with a lot of college courses (incl. 3 semesters of calc, 1 of ordinary differential equations, and a year of engineering physics).

The value of the community colleges in teaching courses which are often 500-student lectures even at smaller universities canNOT be overstated; instead of a lecture with the actual prof., but the one-on-one experiences mostly with the Teaching Assistants (TAs), "learning" can be harder at a 4-yr institution in the big lecture courses.

Get things like Psych 101/Economics 101/Sociology 101 (the intro courses to these fields, often required as part of the checklist of university requirements for a 4-yr--Bachelor's--degree) done at the cheaper rate, but ESPECIALLY take any of these, if you are interested:

Calculus
Calculus-based Physics
Basic Inorganic Chemistry
Basic Organic Chemistry

These can be much better learning experiences at a jr. college, and give you a firm foundation for a better 4-yr degree.

Most 4-yr schools will require a high school diploma, but a 2-yr degree from a good jr. college, with a great GPA and recommendations from actual college professors would put you in a class by yourself in terms of applying to colleges...

This is assuming that you may not have completed every course required for your state's high school diploma; of course, you could check w/your school's Superintendent about community college courses you could take to fulfill the remaining requirements, then get your high school diploma with doubly-counted credits.

For instance, I took Econ 101 at a jr. college and was not required to take a high school level course in it. Then my four-yr. university also waived my need to take THEIR Econ 101 course. So ONE jr. college course actually fulfilled TWO requirements, one at the high school level, one at the university/Bachelor's level.

That might be the way to go.

You can do dual enrollment before graduating high school. My daughter is a senior and taking college classes for free that way.

Usually they accept juniors and seniors, but I've known kids in 8th and 9th who get accepted. As long as the academics and entrance test scores are there, you'll likely get accepted.

You can take college classes while I. High school. I took astronomy at a community college in my senior year. I was the first student at my school to do it. It was fun.

in the meantime can get dual enrollment in your high school. my daughter was able to take classes that got her college credit while still in high school.

didn't have to pay for the class either

you'll have to check the individual colleges' criteria for admission, they should have something on their website about evaluating the credentials of international students if you're outside the US

11th grade, I think with communty college you can do duel courses but otherwise yes.

I knew people that took a class or 2 when they were seniors in high school

You can apply in 11th grade.

Depends on where you live.

also if you have exceptional IQ you can get in

No, not unless you're Sheldon Cooper

If youre a genius then there are probably workarounds... however for normal situations, yes its a requirement. At least where i live.