If I have a “Latin American Spanish” learning kit- is that of Mexico/ South America/ where?

I would like to learn the Spanish/ Castilian of Buenos Aires, Argentina, although, for many reasons, the Spanish of Mexico would be good to learn, too.

I have a language kit that purports to be of a "latin american dialect", but as this seems to cover such a vast territory, I have no idea what this means. Please advise & thank you.

Also, I have another similar, albiet slightly different, question going at the same time.