Learn it before you need it
It seems that more people buy solar cookers during times of uncertainty... And pray that uncertain times pass quickly. Meanwhile... if you are new to solar cooking it is imperative that you practice. If you are new to your solar cooker, it is imperative that you practice. Develop your skills, learn what your solar cooker can and cannot do - before you must rely on it.
Practice, ask a friend, cook a simple meal... practice will pay off.