SQL Server login practice

After reading and somewhat understanding security components (principals, securables, and permissions, fixed roles, user-defined roles, etc.), I like to get good skill by practicing them.

Question: Where can I find typical scenario statement to apply in my SQL Server installation and test them to make sure I have done correctly?

for example:
- make user1 sys admin
- make user2 database owner
- make few other users and assign them different roles
- assign roles
- process how to test them.

I can make my own examples; but most likely they may not be as good as thoughtfully designed by an experienced SQL Server admin.