I’m a university math lecturer. High school GPA means NOTHING. The amount of work required to get an A in college is ten times what it is in high school.
Go to youtube and find a prep course with online tests and PRACTICE PRACTICE PRACTICE.
Good advice. I once worked in adult education at a community college, helping people prepare for the SAT. They had a high school diploma and I was amazed at how some of them passed as they lacked basic skills.