Most likely hamburger, as hamburgers are not traditional Spanish foods. Also, tortillas originated from Mexico and pinatas from Spain (most likely), and sauce is such a generic type of thick liquid that every country has, so that it could have no way originated just from the Spanish language.
there are 14 present tense verbs in spanish
You would use "estar" in a sentence like, "voy a estar con mis amigos" which means "i am going to be with my friends". i don't see how you can use it in the examples you put.
