2021 International Residential Code

Hello and good day to you. I am looking to see if anyone has any tips or could point me in a direction that would help me to learn IRC 2021. I have done InterNACHI’s ‘2021 International Residential Code® (IRC®) Exam Study’ Online Course. I also have the NACHI flash cards and have done a lot of the practice test. But none of them seem to help and I did poorly on the IRC test. Would appreciate any suggestions going to go back and study more.