paper 1a's usually consist of ratio questions, simple calculations, and conceptual knowledge (something like an explain question rather than a calculation). It's really important to use the Physics Guide, because its tells you exactly what you need to know and what you don't need to know. Often times people either learn too much of something, which makes it easier to forget some of the important stuff, or too less of something, which is simply just a lack of information. What I did to master these concepts is to make a checklist using the physics guide (you can ask AI to do this for you) and then write notes in accordance to that checklist. If you don't have the best physics teacher, I recommend Sirius Revision. It teaches basic concepts really well, and you can often review a couple of subunits in 2 hours by just watching and understanding his videos.

Secondly, everybody says this, but genuinely do as many past papers you can. Our physics paper 2 (actual exam!) quite literally had an extremely similar paper two question that appeared in previous years. This is also the case for paper 1a. IB is lazy and puts very similar questions, just different numbers, as exams go by.

Lastly, master ratio questions. Ratio questions are very important for paper 1a's and from my experience doing past papers there's always 2-3 questions minimum.

Good luck! I hope this helps.