I was not able to login to my magento admin using the default password.
The username and password for the instance are in the file
Regarding the redirection, it is probably an issue with the host to generate the internal URLs. The base_url is stored in the database in Magento. You will need to modify it.
To check what is the base_url execute this queries:
select value from core_config_data WHERE core_config_data.path ='web/unsecure/base_url';
select value from core_config_data WHERE core_config_data.path ='web/secure/base_url';
If the result are the old ones, change them to the new one.
I hope this can help you.