Do I need to create the questions up front?
Two ways to define questions
Questions are kept in a project. You can add them to the project and then use them within a study. This means: Your study will aim to answer those questions that you have used inside that study.
The other way to define studies is: Go into the study, add a question. It will be used in that study and will also be added to the project at the same time so that you can use the same question inside another study.
Why would I use the same question in two studies?
Sometimes, it takes more than one study to really answer a research question. Example: The question is "Why do so many people start the registration process but then stop?". You might need one study to ask the users about it. Then, you change the registration process and do another study: an A/B test with the old design versus the new design. This second study (the A/B test) would use the same question as the first study. After the second study, you would really know whether you've solved the problem or not.