I would first address issues of health and safety - a student who is hungry cannot learn well, and a student who doesn't feel safe cannot learn well. I would work to ensure free and subsidized meals remain available at school, and put in place comprehensive plans to address school bullying and other behavior issues.
Beyond that, I consider a strong focus on early literacy and numeracy to be critical in setting a student on the path for later learning, so early remedial intervention for struggling students will be a high priority.
Third, students must receive a high-quality education that best prepares them for the life they desire beyond high school, whether that is a 4-year college, trade school, the military, or direct to work.