Standardized testing is the biggest hurdle to overcome in your junior year of high school. Of course, IB activities are also a big deal during this time, but getting that SAT or ACT out of the way is the biggest deal. So how can you tackle these new experiences?
As someone who took both SAT and ACT, I definitely recommend taking both tests and seeing which you like most. Use those fee wavers! If you're strong in English and Reading, I definitely recommend the ACT because I was able to score enough points on those categories to make up for my totally lackluster math and science sections. The SAT is more like the PSAT that you've hopefully taken at least once in your high school career. If you like it and you're comfortable with it, stick with an SAT!
Additionally, I recommend doing SAT or ACT prep. Buy the books, take free online tests, take advantage of your resources! Khan Academy is free, and even Google has free ACT practice questions.
When it comes to taking the SAT or ACT, I recommend taking them either in a familiar environment (like your very own Coral Reef) or close to home so you can get more sleep. Additionally, bring snacks and rest up, but you already know that from your years of testing.
And finally, I recommend taking the test as many times as you need. To get the ACT score I wanted, I took the test 5 times. Just be aware of the fact that this can be a costly venture if you don't have fee wavers, or if you run out.
Happy testing! This will be over before you know it, and senior year will (hopefully) be a breeze!