You can create a new organization by either setting up a new organization or converting an existing personal account into an organization.
About organizations
Organizations are great for businesses and large open-source projects that need multiple owners and administrators, grouped together with teams that determine affinity and repository permissions.
Creating a new organization from scratch
Create an organization to apply fine-grained access permissions to repositories.
Converting a user into an organization
You can convert your user account into an organization. This allows more granular permissions for repositories that belong to the organization.