Help with Creating ODBC Connector using SQL Server Authentication

I am trying to setup an ODBC connection.  The server is Windows Server 2012 running SQL 2014.  The client machine is a Windows 8 64-bit PC.  

On the client, I go into the SysWOW64 folder and run the odbcad32.exe as an administrator.  When selecting the authentication method, if I choose WIndows NT authentication I have no option of typing a username or password.  Therefore, I am under the impression that it is using the Administrator account that I used when I launched odbcad32.exe.  Using the Windows NT authentication mode, I am able to connect to the database.  

If I select, SQL Server authentication using the same Administrator credentials that I used to launch odbcad32.exe then the connection fails.  I receive  the following error:

Connection Failed:
SQLState: '28000'
SQL Server Error: 18456

I would like to use this method as I want to connect with a user that has limited rights to a database.  I double checked my SQL server and it is configured as "SQL Server and Windows Authentication Mode."

Any help is appreciated!