To create new users, login as admin and go to Settings/Users and Companies/Users and create new users as you like.

To change the database, use the database selector URL .../web/database/selector, use the database manager .../web/database/manager to create, delete, copy and backup databases.

Usman, Thanks for the update but once i clone the repo and i cant login to access to settings and all. I would like to know how to start fresh when i cloned , i don't have any account , i want to create an account and then login after i cloned the system. 

Thanks in advance

https://www.odoo.com/documentation/user/14.0/general/odoo_basics/add_user.html