Hi there! First of all, I want to say good luck on your journey, It's not easy but if you stay consistent with your work I'm sure you'll do well
Honestly, biology and chemistry will be just fine as long as you don't leave the revision till the end, as they can both be quite content-heavy, it's better to spread revision out so you can cover it all. As for classes, stay focused and try to ask as many questions as possible, as staying engaged will be incredibly beneficial to learning both subjects.
For psychology I made a quizlet for my final exams, I know it won't be too helpful at this stage but if you'd like to save and come back to it during mocks/ exams it might be a helpful tool, I hope it can help
The link is https://quizlet.com/797234951/ib-psychology-may-2023-flash-cards/?i=3cnygs&x=1jqt
I took HL bio, chem, and psych, SL math, English, and French, so if you have any questions about any subjects in particular, feel free to ask!