Manete is literally "wait," but there's no equivalent expression. Noli timere is another, meaning "don't worry."
Our meaning of class (as in class at an educational institution) did not exist in Latin. Medieval Latin, however, introduced "Classis" (originally "fleet" in Classical Latin), as the word for class. If you mean social rank, though, "ordo" would be the best rendering.
The Cambridge Latin Course is a well-known beginner Latin course in the series of five textbooks. See 'related links' for more information.
To warn Europe to stay out of Latin America
Of course Latin - oxygenium
utique
"To stay" in Latin is manere. The imperative (which you might use, for example, when telling your dog to stay) is mane. Or, if you have more than one dog, manete.
In pig latin, "Stella" would be pronounced as "Ella-stay."
Gustatio.
Yes, of course that Italy is a Latin country
They stay out of their minds of course.
Subsisto positus
"Mane mecum" would translate to "Stay with me" in Latin.