For this case we have to:
According to the conjugation of the verb "ir(go)" imperative (simple perfect preterite) we have:
"I went": It would be translated into Spanish as: "Yo fui"
On the other hand, according to the conjugation of the verb "ser / estar (to be)" indicative (imperfect preterito) we have:
"I was": It would be translated into Spanish as: "yo era / yo estaba"
Answer:
"Yo fui"
"yo era / yo estaba"