I need the subsidy password

A request for a Subsidy Password means the phone is 'locked' to a specific network provider (SIM), so it's the same as an 'unlock code'.
Provided you've had the phone for the minimum time the contract runs for, you can request the unlock code from your provider - ie the network the phone originally worked on.

To obtain your IMEI number try entering:
*#06# in full (including asterisk) and the phone should display it for you. As far as I know you don't need the IMEI in order to unlock the phone.

Hope this helps - I'm not an expert.