Preparing for the first Sprint
In Scrum, every Sprint is treated exactly the same as any other Sprint. It is a time-boxed event in which the Scrum Team delivers value by creating an increment of potentially releasable software. No Sprint is special in that respect. Some teams, however, especially teams inexperienced in Scrum, tend to treat the first Sprint a bit differently than the others.
Avoid the Scrum 0 anti-pattern. A Scrum 0 is a Scrum dedicated to setting up infrastructure, creating a design or architecture, initial backlog refinements, and other preparatory work. Scrum 0 is just a set of preliminary activities and does not produce an increment of potentially releasable software. Sprints designed not to produce a Done increment undermine the Scrum principles and should not be pursued.
A common misconception about the first Sprint is that because it's not expected to produce user-side functionality, then it's a special Sprint and can be used as a repository...