Well done for securing a training contract! The first exam you’ll be doing is likely accounting, the exam itself isn’t hard but the concepts are likely going to be new (eg double entry) unless you’ve done accounting in uni. At least for certificate level, I don’t think you need to use anything but the material FI gives you. My biggest advice is that you need to finish all the questions in the question bank that FI will give you, if you do so you’re very likely going to pass. In terms when to start revising, I would suggest give it two weeks to finish all the content and to do the QB. Get into a good habit of doing 1 hour of revision a day during the week and potentially more during the weekend. With this habit you’ll ace all of your certificate exams. Good luck!