No matter what country you are in, expressing gratitude is an important part of communication. If you want to express gratitude in Spanish, then you will need to know how to say "thank you." Saying "thank you" in Spanish is quite easy. In fact you probably already know the basics.
Say "gracias." Spanish speakers use "gracias" a bit less than English speakers use "thank you," but it's generally used in the same types of situations.
Use "muchas gracias" if you want to say "thanks a lot." If you want to over-do it you could say, "muchas, muchas gracias."
Say "estoy agredecido," if you are a man, or "estoy agradecida," if you are a woman to say "I'm thankful."
Use the expression "to give thanks" by saying "dar las gracias." If you want to say, "I give thanks," you would say "doy las gracias."