Translation:The pig went to Mexico to learn Spanish.
Why? The few of us who might actually live or work on a farm in Spain or Latin America certainly could learn the required special vocabulary there! The rest of us (at least, those of us no longer teenagers) would only forget. Duo does include general kinds of words (like farm, farmhouse, gate, bucket, wash, clean, horse, cow, pig, milk, meat, etc.). Plenty for general purposes, I think!
I don't know if the answer is given somewhere else, but I would like to know which animals the Spanish use to describe humans - in English and German you have the stupid / lazy cow, the filthy pig, the silly goat - are they used the same way in Spanish? What other animals are used for their traits to describe humans?
lee, I think you are confusing two words.
Estar = to be. Preterite, first person singular = estuve (I was)
Ir = to go. Preterite, third person singular = fue (he/she/it went)
Note: Ser also = to be (not applicable in this sentence, but conjugated like ir in the preterite)