Respuesta :
Soy (yo form, present tense) - use when describing traits about yourself (permanent traits, not thoughts/feelings/locations/etc)
Era (yo/el/ella/usted form, past tense) - directly translates to 'was.' use when describing something in the past
Yo - soy
Tú - eres
Él, Ella, Ello, Uds - es
Nosotros (as) - somos
Vostros (as) - sois
Ellos, Ellas, Ustedes - son
You use ser when you are telling time, descriptions, occupation, and nationality
You would use estar when you are telling a place or location, and feelings