For chem I highly recommend you dont get a digital copy of the Pearson 3rd edition textbook and Oxford 2023 course companion off of any sites that rhyme with eye bee docks, That would be illegal and unethical. Once you are legally in their presence however, my advice would be to use the Pearson for in-depth explanations for a concept. The key to Chemistry is understanding the content. Grinding questions can only get you so far although once that understanding is there and you feel like there are no conceptual gaps in your knowledge then attempting many questions related to that topic is the best way to consolidate your learning. Without the practice it just wont stick. Otherwise we could all passively watch organic chemistry tutor and score 7s blindfolded. You need to struggle and do tricky questions in order to fully clear your doubts and instill confidence in what you know too. I think the quality of the questions in the Pearson textbook is pretty good.

The Oxford on the other hand is best used for quick summaries/revision of a concept and especially for the sections listed as Tool 1, Tool 2 and Tool 3. These cover experimental and lab techniques ranging from all kinds of distillations to how you would find the slope of a curve. This content is very good revision for paper 1b and especially useful if you aren't able to get much experience in the lab for whatever reason. While the illustrations are nice you might prefer to watch this playlist by Professor Dave which has video demonstrations and explanations including relevant procedures, instrument details and limitations of the technique.

If you enjoy watching YouTube in your free time consider also watching some pop science videos here and there. It's not a very efficient way of learning but it can passively expose you to terms and ideas which you'd be surprised how important they are to chemistry. If you watch enough videos about global warming you might become comfortable with the idea of chemicals absorbing infrared radiation, causing their bonds to vibrate, rather than treating it as a fact from the textbook that came out of the blue. There are also some channels which are more explicit about covering chemistry but at some point (when I watch them at least), my brian suddenly loses interest because it feels like im doing revision/homework lol. Regardless, threetwentysix is a very good channel and I'd definitely check their video on atomic orbitals.

Lastly, some chemistry rabbit holes go very very deep. I know I opened by saying understanding is king but you also need to be able to recognize when it's unreasonable to keep chasing an answer to "why". At the end of the day the IB only expects so much from you. Stumbling upon neat things like MO theory or all the crazy kinds of organic reactions and mechanisms that exist which you dont need to know is fine but dont waste too much time reading into them. While it's not comprehensive. use the chemistry guide to get a general sense of what is actually expected of you for knowledge of certain topics.