account holder name,address,voice mail code, account code, sim card code , what else ??

Since SO doesn't have most of that information, you won't need it either. You will need the phone number, and the current password (aka voice mail code) so you can change it to your own new password.

And once I get sim card and all the info what my next steps should be?

Put the SIM in your phone, dial 611, use the existing password to access the system, change the password to a new one, set the voicemail options to your preference, and start using your phone.

If I to buy from someone used SO sim card what information should I be asking seller for to be able fully assume account - account holder name,address,voice mail code, account code, sim card code , what else ??

And once I get sim card and all the info what my next steps should be?

Thank you.