You don't need to take your theory exams before you start flight training, but there's no problem if you'd like to do that.
We'd recommend studying for your exams as you go through flight training. All exams need to be passed before you can take your final skills test. You will need to pass your Air Law exam before you go solo, but we'd advise taking the three below exams within the same exam sitting (which lasts for a week for each sitting, you have 6 to use so it's best to do 3 per sitting to leave time to resit if required)
Air Law: This exam is crucial as it covers the regulations, rules, and procedures that govern flying. Understanding air law is fundamental to ensuring the safety and legality of solo flights.
Operational Procedures: This subject focuses on the standard operational procedures and practices required for the safe conduct of flights. Knowledge in this area ensures that the student can handle various operational scenarios effectively.
Human Performance and Limitations: This exam deals with the physiological and psychological aspects affecting pilots. It covers the effects of flight on the human body, including stress, fatigue, and the importance of maintaining good health.
Passing these three exams is a prerequisite for ensuring that the student pilot has the essential knowledge required to handle a solo flight safely and competently.