Hi Swapril,

  If this is the first time you have run this locally, then there are not yet any accounts set up for you to use.  Mendix always creates one Admin account, and generally this is MxAdmin with a password '1'.  You will need to first log in as MxAdmin and then create other accounts.  Password details for MxAdmin are configured in the Modeler under the 'Administrator' tab of your project security.