"Soy de México" means "I am from Mexico".
'Soy de Cuba.' 'Soy' is the first person conjugation of 'ser' which means 'to be' (in regards to an essential quality of a person, not a condition - which is what we use 'estar' for.) 'De' means 'from.' Cuba is the same spelling in Spanish as it is in English, though it is pronounced "Coo-ba" instead of "Cue-ba."
"Soy de España" means "I am from Spain" in Spanish.
soy de... means: I am from... literally: "I am of..."
Yo soy de Portugal means 'I am from Portugal.'
i am from...
If by America you mean USA Soy de Estados unidos if you mean the continent soy de America
"Soy de aquí" in English means "I am from here."
I am from Venezuela
"De donde soy yo" translates to "where I am from" in English.
No soy de Milano would translate into something along the lines of "I am not from Milano".
"Eres de Cuba" in Spanish means "You are from Cuba." It is a statement asking about someone's nationality or place of origin.