To get started in terms of what to build, Scrum requires no more than a Product Owner with enough ideas for a first Sprint, a Development Team to implement those ideas and a Scrum Master to help guide the process.
What is a Scrum Master?
A scrum master is the scrum team member tasked with fostering an effective and productive working environment and guiding others to understand scrum values, principles and practices. Scrum masters tend to be people-oriented, have a high level of emotional intelligence, and find joy in helping team members to grow.