For my freshman year math course I covered Algebra 1. I used the Saxon Algebra 1 book. My parents would run through the lessons with with me and provide more in-depth explanations of the material. I would then attempt the exercise questions on my own. After I was satisfied with my answer I would check my answers with my parents, and they would help me re-work any problems I got wrong.
By finishing the book I had covered all topics in a typical first-year algebra course, from proofs, statistics and probability to algebra-based real-world problems. With Algebra 1, I began developing the more complex understanding required for more advanced mathematics.