We have received a 2 year Green Card after entering on a K1. We just moved to a new apartment.

Do I, the USC, need to file a change of address form, AR-11 ? I did Sponsor him initially- I am still responsible to do this?

Does he, the beneficiary, use the AR-11 form? He is self-employed, so what should we put as his work address? His home address? Or leave in with "n/a" ?

Are we considered "pending"

the permanent resident needs to file the AR-11 which you could do online...
https://egov.uscis.gov/crisgwi/go?action=coa



the sponsor/ us citizen needs to file the I-865
http://www.uscis.gov/files/form/I-865.pdf

Thank You