I'm assuming translations aren't necessary for every example phrase, so:
모두 일어서세요, 모두 일어나세요 (everybody stand (up))
모두 일어날까요? (shall we all stand?)
모두 자리에 앉으세요, 모두 앉으세요
모두 자리에 앉을까요?
모두 선생님께 인사하세요
모두 선생님께 인사할까요?
똑바로 서세요 (stand up straight, properly, as in straight up, straighten your back (could be a little strict, confrontational, depending on the situation))
일자로/일렬로 서세요 (stand in a line, single file)
The above are fit for a teacher to use when addressing those lower, e.g. students. The question forms are dimilar to "Shall we, shall... Should we..." and have a softer vibe, though can be overused. You could add 여러분 (everyone) (at the start or end) and 이제 (now) (after 여러분 at the start: 여러분, 이제 일렬로 설까요?) to soften the suggestions.
This type of 존댓말, ~하세요 (일렬로 서세요, 책 닫으세요) may be more courteous (and showing more respect towards the listener) than a different 존댓말 and what others may use, e.g. ~해요 (일렬로 서요, 책 닫아요), which shows less respect towards the listener, but is nevertheless fit for a teacher-student relationship (with enough age difference, among other things). Both can be used, and both are used, but I imagine most students might prefer ~하세요; it's more courteous and sounds more pleasing to my ears, personally.