First of all, don't be discouraged by your initial struggles in physics. Many students find this subject challenging, but with dedication and hard work, you can improve and succeed.
One tip for starting from scratch is to familiarize yourself with the basic concepts and principles of physics. This can be done through reading textbooks or online resources, such as Khan Academy. It's important to have a solid foundation before diving into more complex topics.
Another helpful tip is to practice solving problems. Physics is a subject that requires a lot of problem-solving skills, so the more you practice, the better you will become. You can find practice problems in textbooks, online resources, or even from your teacher.
In terms of books, some popular choices for beginners are "Physics for Scientists and Engineers" by Serway and Jewett, "Fundamentals of Physics" by Halliday and Resnick, and "The Feynman Lectures on Physics" by Richard Feynman.
Lastly, don't be afraid to ask for help. Your teacher, classmates, or tutors can provide valuable insights and explanations to help you better understand the material. And remember, don't give up and keep a positive attitude – with determination and effort, you can achieve an A in physics!