Many trainers send a package with literature, agile tools or small goodies before the start of the training. Therefore, they ask you for an address to send these materials to when you register.
The surprises are meant to complement the training to help you get started with agile. Most of the time, there is current literature related to the content of the training in the package. This helps you after the training to deepen what you have learned and to answer questions.
If your package has not reached you by the time of the training, don't worry. The contents are an attention to you, so that you can deal more deeply with the agile work and you have the chance to collect directly after the training the first Scrum Education Units (SEUs) for the extension of your active membership in the Scrum Alliance.