A baseline assessment is designed to find out how much you know about a topic. It is not something you revise for and it is not something you can 'pass' or get 100% in. You should attempt all questions, even if it is a guess, and move on if you are stuck because you can come back to those questions and you might miss questions you know the answer to. Your best is good enough.
Download the baseline assessment. You need to allow the security exception.
When you have completed it, there is a big button at the end. Only press it if you have finished and your teacher says it is okay.