Because the Development Team is the ones doing the work, they are best suited to inspect and adapt the progress toward the Sprint Goal. At minimum, this is done every 24 hours through the Daily Scrum. It is the Scrum Master's responsibility to teach the Scrum Team the value and objective of each Scrum event in order for them to optimize the benefits of each event. Because the Daily Scrum is owned by the Development Team, it is up to them on how they should run it but the Scrum Master can provide guidance to ensure it adheres to the Scrum guidelines.

Explanation
Explanation:
The Development Team may need to order the Product Backlog as they would know the most about technical limitations, risks, or dependencies between Product Backlog Items. As User Stories is a localized practice, Scrum does not govern it or dictate the practice. How the team describes the items is up to them as long as it has enough information to be transparent and understood.

Working software is the primary measure of progress. Scrum is based on empirical process control theory where delivering working software frequently and measuring the impact helps the Product Owner maximize opportunity for the business to deliver value.

Explanation/Reference:

Multiple Scrum Teams could have the same Sprint start dates but it is not mandatory as the importance is on being able to integrate their shippable Increments at the end of their Sprints.