It won't make too much of a difference, I sometimes think if people spend too early starting to make notes, in name of efficiency, they might not be taking the time to absorb the content and UNDERSTAND IT. I personally think you should refrain from making notes, rather just read through the textbook and see whether you understand the concepts and what they are talking about-UNDERSTANDING is so much more important than just mindlessly copy and pasting from textbooks (or paraphrasing in many cases-also inefficient way of learning). Just my two cents. I know it is tempting to get notes done as soon as possible-but i truly think this is the best time to slow down and just take the time to absorb some content in.
Also textbooks can go beyond syllabus dotpoints-so arguably simply summarising the textbook is being non-selective and you will be writing down irrelevant information, I personally would make brief notes if I do make any notes and wait for the class to direct my focus correctly on stuff-->which is another reason why I would rather prefer to get an overview now rather than just go straight into the deep end (because you might not know what is relevant to summarise right now even with dot points as guidance-->i.e. depth, breadth etc).
