If you need a PUK code to unlock your device, that comes from your network carrier. (You may also be able to access it if you have an online account - network dependent).
Ok so does the SIM itself have a passcode or the device lock?
Myself I would factory data reset the device, start again and set your SIM up. Default code for SIM is usually 0000 and then you can change it to something you prefer. 6 digits is recommended.