Am I required to take the online and practical training (i.e. in-yard and in-cab) concurrently or within a certain timeframe?

The online training needs to be completed within one year from the time you start the course. It’s recommended that the in-cab and in-yard training be completed within one year after completing the online training, however it could be taken concurrently if you choose to do so. 

Learning Paths that require a practical component provide you with information for the instructor demonstration and practical evaluation that will be completed at a training school.