Good question, and I appreciate your concern. In general, there is no limit to the number of, dollar amount of, or total dollars raised from scholarships for your education. Most scholarship programs are one-shot opportunities with dollar amounts limited by the size of the program and / or the eligibility requirements. What you do is apply for any and all scholarships for which you are qualified. Carefully watch application dates and which school year they’re for.
A good place to start is the Office of Admissions at the school where you’re going. The more general scholarship programs will have brochures you can take, and the people that work there know everything about the bigger public programs and you should talk with some of them. Ask about academic scholarships while you’re there.
Another category of scholarships are ones that are targeted towards your field of study; let’s say your interest is teaching science at the K-12 level just for an example. Look at websites for anything teachers might be interested in like example lesson plans, continuing education credits, how to engage teenage boys and help you build something big for a science experiment. Look for organizations that promote women interested in STEM, big companies in your area, any organizations your parents belong to. Excuse me for asking, but if you speak a second language, want to work with at risk students, or if your parents have a disability (I have MS and my daughter found a scholarship for that), be sure to look for those. I forgot that teaching was just an example, but I hope you got the idea. Best of luck.