Building US credit from zero, a starter guide

No US credit history is one of the first walls people hit. Common first steps: get your SSN if you are work-authorized, open a secured credit card or a student card, keep utilization low, and never miss a payment. Some banks and card products are built for newcomers and do not require prior history. Credit compounds, so starting a few months earlier genuinely helps later with apartments and cars. What worked for you to get started?