If you are referring to your college application essays, your teachers at school are going to be your best bet at free professional help. You don't necessarily have to ask the English teacher you currently have now--any of your past English teachers from previous grades or any other teachers you feel comfortable with are also great candidates to ask for help from. Other people you could ask to review your essays would be your guidance counselor at school, parents, family friends, peers/classmates, alumni from colleges, current college students, etc. It's normal, and even expected, for students to use their network of friends and family to their advantage and to not be shy about asking for help. Most people are happy to help, or if they can't, will be able to direct you to someone who will. In terms of programs that might offer free essay reviews, you might qualify for programs such as these: https://www.collegepoint.info/nominate/
You may have local programs around you such as Communities in Schools, QuestBridge, or AVID that might be able to help as well.