How are many credits are earned each year?
You can earn up to a maximum of four credits per year as you earn and pay social security taxes.
Okay, and if I can't apply for retirement benefits online, where can I call or do I need to come personally in your Social Security office?
Yes, you can call and apply by phone.   You can call at 1 - 800 - 772 - 1213 ,  or TTY 1 - 800 - 325 - 0778 from 7 AM to 7 PM Monday through Friday