You can apply for an SSN card at the SSA office preferably within the 90 days or 2 weeks after your arrival in the US. You need to bring a valid or unexpired Arrival/Departure Record I-94 Form together with your passport. You need to go to this website: https://i94.cbp.dhs.gov/ You just need to print the I-94 Form and the SSN FORM at https://www.ssa.gov/forms/ss-5.pdf . And please don't forget to also bring your passport.