Your are getting errors when trying to connect to the database using the built-in SQL database credentials.
During installation, SQL Server Database Engine is set to Windows Authentication mode.
Change Authentication to mixed mode.
To change security authentication mode:
- In SQL Server Management Studio Object Explorer, right-click the server, and then click Properties.
- On the Security page, under Server authentication, select the new server authentication mode, and then click OK.
- In the SQL Server Management Studio dialog box, click OK to acknowledge the requirement to restart SQL Server.