How do I create "groups of users" and set permissions in SQL Server?
What you can do in sql server is to create a group of permission.
They are called Database Roles. You can use pre-build roles or create some new.
https://docs.microsoft.com/en-us/sql/relational-databases/security/authentication-access/database-level-roles?view=sql-server-ver15
About the group of users you can't with the sql authentication but if you use the windows authentication you can relay on local user groups (uased as login in sql server) or active directory user groups (add them as login in sql server)
https://docs.microsoft.com/en-us/sql/relational-databases/security/authentication-access/create-a-login?view=sql-server-ver15