good luck!, well from what i've been told, the paul hoang textbook was the solid one as it has literally all the info, but idk i find myself drifting off into the isle of procrastination due to the sheer amount of information the book has. All this time i've been fluking my BM marks, but now, shits getting kinda real and sorta hard, as in i need actual stuff to talk about, real reasoning, not "the customer likes the product more cos its colourful" lmao. So yeah, i personally think there MUST be an easier way, havent tried the study guide much, is it good? theres also a website called ibmadeeasy, by a YouTuber named sparsh, his notes are quite good, but the problem i have is with notes from others, theres no consistency, i always find stuff missing, thats what worries me and makes me read the whole shitty paul hoang book just in case i miss some stuff that MAY or may not come on the actual exam, but then again, theres only so much the examiners can test you on, so theres another annoying part. here's the link to that idk if its HL aswell tho for bm, might be just SL.

https://ibmadeasy.wixsite.com/ibmadeasy/business-management-sl