Resource types

Hi Sundeep
If I understand both of these questions correctly you need to have a good look at Roles. The Admin can assign a user (teacher) as a Course Creator which provides that user with the ability to create a course and teach in it. The Admin can also assign users as teachers in a course then remove their access when not required (or provide them with a different role that is not as high as a teacher).
I hope this helps
Cheers
Teresa