I don't understand why people say chemistry is hard, I personally found it quite easy. Perhaps it's to do with the way the content is taught to them, it's a content heavy subject and you do need to know concepts with a lot of detail but doing a few exams allows you to recollect all this knowledge and you can implement it into your memory a lot faster.
If you are skipping units 1/2, I suggest you buy the 1/2 textbook now and find resources from ex or current(preferably) students and revise it over the summer holidays or even now if you aspire to do really well.
