Are Physics and Maths tutor flash cards any good?

I’m rlly stressed out about science as I’ve never done well in a science test through all my yrs but I’m still put in triple. I’m trying to make my own flashcards and notes using freesciencelessons on YouTube but I’m rlly worried that they don’t have all the information that I’ll need. On the website Physics and Maths tutor there are pre made flash cards n idk if they contain all the content I need to know. Just want to know if if it’s any good to use these flashcards