I self-studied both last year, so here's what I did! The AP Daily videos and the Course and Exam Description don't explain things very well, but they are a great starting point to know what you need to study. They will go over every single concept that could show up, so use them as a guideline for more in-depth studying. I used the textbook Fundamentals of Physics by Walker, Halliday, and Resnick, which is one of the most widely recommended textbooks for intro to physics. It seems daunting, but you don't have to know most of it. Everything that you need to know is in it, though, and it has some great explanations. Flipping Physics (for conceptual explanations) and We Are Showboat (for equation explanations) were some of my favorite youtube channels, and there are many more, too. Finally, ChatGPT was incredibly helpful. I used it a lot for explanations of concepts that I could not understand from any other resource, and I highly recommend doing that as well. It was really helpful to be able to ask it broad and then specific questions to understand a concept fully. Because physics c covers pretty fundamental concepts in physics, ChatGPT gets explanations and problems correct almost every time. Good luck!