Let's be clear: getting a full scholarship is very rare. Fewer than one percent of college applicants end up getting to go for free. It takes more than just being a good student who wrote a good application essay. But still, one percent is still thousands of students a year, so you may want to do some thinking and planning, just in case.
Here's a simple rule to help you know how to think about full scholarships: you should not pass up a full ride. If you apply to a school and they offer you a full scholarship, go to that school.