I have a month and half before school with nothing planned. Is there anything useful I can do other than sitting at home all day?
Depending where you live you could volunteer with refugees; there’s lots to do even in the US. You could volunteer at a local library or old folks home. Any kind of volunteering is good. Practicing a sport, an instrument or art (visual or performing) is also productive for self betterment. If you write you could write. You could look for summer work walking dogs, mowing lawns or other irregular jobs. The best thing I would say is just to get out of the house and limit time spent on social media or watching tv.
SAT or ACT Prep?