The whole organization needs to go through trainings in order to become Agile, but the most critical role to get things right is
Product Owners. They will need to learn how to set up team’s goals, how to create and prioritize backlogs, how to work with stakeholders and how to motivate the team.
Product Owners should be purpose driven, independent and ambitious, have in-depth knowledge of the product and great soft skills.
It is very important to organize an internal bootcamp or academy for Product Owners before undergoing the transformation so that they learn and practice new skills, while getting to know each other and building a strong network which would later enable collaboration amongst Agile teams.