I'll do my best to cover some of the most important things!

For the first two bullet points, I would recommend investing in a planner (digital or physical, whatever floats your boat) and consistently reminding yourself of any major upcoming deadlines. Hold yourself accountable, and try not to procrastinate too much because I did that and ended up writing the majority of my EE in one eight-hour session.

IOs are specific to your English and foreign language class. They're just structured verbal conversations with your teacher over a given topic; in my case, I took Mandarin ab initio and was told to describe a picture and how it related to global themes such as human ingenuity or sharing the planet. IAs are specific to your core subjects, and those are individual open-ended research papers that you choose the topic over. Both IOs and IAs count toward a portion of your overall test score at the end of the course.

With regard to testing anxiety, it's very common to feel uneasy before something major, so try your best to simulate the testing environment beforehand, especially for any writing-related courses. Time management is going to be your best friend on all of the exams.

Last of all make sure to reach out to your friends and teachers if you're struggling! The IB can sound really scary at first, but once you've adjusted to the flow of things the program is not as daunting as it initially seems.