How do you say I was born in spanish?

Yo NacÍ en

I was born= Yo nací

To say: "I was born on" (Date) You'd say: "Naci el..." e.g. "Naci el 5 de julio de 1990"

To say: "I was born in" (Place) You'd say: "Naci en..." e.g. "Nací en Guadalajara"