Hello! Besides doing TPO to familiarise yourself with actual exam questions, you can also use professional articles to practise. The most classic type of specialised articles are those related to your major. Such factual articles can allow you to understand more types of English expression, and it allows you to build on your content knowledge pertaining to the subject, giving you the ability to use these content for other components of the exam. Of course, if you have a good foundation, you can consider reading articles of different topics.
If you don't have much time, my advice is for you to just relax and keep up with the habit of reading instead of focusing so much on what to read. Good luck!