That's fine!
The first thing to understand is that Must questions are the basis and foundation for all other questions types. If you can't regularly identify what is true or the case in an argument, it becomes much harder to Justify it, find the Flaw, or perform any other task like Weaken or Strengthen it. So, start with Must first and focus on that--it will help you get better at all other types automatically
Begin by really reading the Ch 4: Must section in the LRB, since that applies to RC as well. But know that Ch2: Basics of LR plays a HUGE role in understanding what you are seeing in Must questions (and all others), so if you aren't rock solid on how all that works (meaning: can you teach it to someone else?), go back into that as well. It's boring but critical to performing at a top level,
It's good also to understand the difference between a straight Must questions and a Most Strongly Supported variant. that in ch4 as well.
Once you've spent some time on Must, come back and let's talk about Flaw and--those can bother be conquered as well.
Thanks!
