There is financial aid available (through FAFSA), based on merit and need. So continue studying well in high school and finish with a very good GPA. That will guarantee you some financial aid. Browse online, ask counselors and advisors about scholarship opportunities, but don't let that interfere with your studies. If you notice that it does, then worry about money later. Focus on your studies first.
Don't worry about the money issue. Like others have mentioned, a lot of people study on loans because even if parents had saved up money, it wouldn't be enough to complete the entire education just on that. There are always subsidized loans available (again through FAFSA) and for these loans, you don't pay interest until your education is complete.
Hope that helps :)