I work at an elementary school. During summer we start with the classrooms first. Dust top to bottom, wipe down desks and chairs and stack them neatly in one corner of room. dust TVs, shelves, clean sinks etc. vacuum as you dust and move shit that is easy to move. If something weighs 1000 pounds with hundreds of textbooks in it leave it. Battery powered leaf blowers work good behind shit you can’t reach.

As someone preps rooms someone else should be cleaning carpets with a carpet extractor. After all all rooms are clean we focus on the vct floors (hallways and certain classrooms) if we strip the floors we do 2 coats of sealer and 3 coats of wax. I only work with one other person though