How do I tell a group to 1) sit down and 2) stand up?

Question

How do I tell a group to 1) sit down? and 2) stand up?

Answer 1

http://www.spanishdict.com/flashcards/5828/classroom-commandslos-mandatos-de-la-clase

Those are flashcards here on this site. Classroom commands, I think it is exactly what you are looking for.

Answer 2

You use the formal or informal, plural command form of sentarse or levantarse (quedarse de pie or ponerse de pie).

You also have to choose between using vosotros ( sentaos) [Spain] or ustedes-3rd, person, plural for Latin America.)