One of the countries in Central America uses Spanish as the official language of the country but also has 23 different Maya groups; each with its own dialect. What country is it?

Guatemala.

It could be Guatemala.

http://www.ethnologue.com/show_country.asp?name=GT

yep it is Guatemala

The country you are referring to is Guatemala. Guatemala is located in Central America and its official language is Spanish. However, Guatemala is also home to a rich indigenous heritage, with 23 different Maya groups that have their own distinct dialects. These Maya groups have preserved their languages and cultural traditions for centuries, adding to the linguistic and cultural diversity of the country.