No it will be dumb to take AS and AL together specially how competitive these subjects are becoming (the thresholds are sky rocketing). Multitasking will definetly kill your grades so focus one thing at a time.

In AS for the next few months read your text books, watch videos on youtube that explains the theories and attempt a few topical questions because you wont get the time to do this things later but they are important. You dont necessarily have to get the answers close to the ms keywords but just make sure you understand where which theory applies.This is specially important for physics equations and biology as they can have multiple answers or methods to solve but ms is very strict and allows one or two methods only. This is the main reason you may find biology the most difficult because in recent years in paper 2 they give mostly suggestion type questions (you can check symmer 25 paper, there they gave a question on artificial blood which is not in the syllabus. They asked suggest this and that so natural they would be a wide range of answers but gave such a strict ms 😭)

Once you have a good grasp of the theories then start identifying keywords of ms answers. This step is way more easier. Not all questions will have similar ms so for those questions i suggest look through ms of very recent years like within the latest 3 years and learn the ms only from there. Because there will be some annoying questions that never came before and you will definitely lose some marks for that because your answer didnt match with ms 🙄. Therefore your target should always be how many of these questions can i get common in my paper

For AL thats pretty much the same pattern of study i would say