You can define how user is redirected after successful login if there is not "old" post information (i'e' unsibmitted form).

To do that You must add configuration value:

key=RedirectAfterLogin,componentType=SecurityUserGroup:<group_id>

value= address to redirect (will be used in header: location(...) )

Note: If user belongs to some security groups (more tharn 1), the first one will be taken.
(With function $securityUser->getFirstSecurityGroup() )