The course is set up so that candidates who have reached the point of being offered a course can go from having no knowledge of trains to be able to drive trains safely, so no real tips to give as far as the course is concerned.
But you must be prepared to make good notes, engage with the trainers and your classmates and don’t be afraid to ask questions about anything you are unsure of, your going to be tested on it at some point so be sure you have an understanding.
Be prepared to put some work in during your own time, to make sure the subject matter during the classroom phase of training is sinking in and being retained.