@chadmat I created new login and also mention default database name.the correponding code is following below.
/*Following code corresponds to the creating the new login and password*/
CREATE LOGIN Mary5 WITH PASSWORD = 'enterStrongPasswordHere'
/*Following code cporresponds to the mentioning default database name*/
ALTER LOGIN [Mary5] WITH DEFAULT_DATABASE=[LoginTesting]
Know I want to add permissions like sysadmin and also I want to map my database to username.
How can I do this through query format.not in GUI.