Getting the best performance
Getting the best out of an inexperienced cast is tricky, but play to their strengths. Occasionally a timid child can rise to playing the 'very angry ogre'. But usually for naturalistic performances, playing to type is easier.
Don't push them to 'act' let it flow whenever possible.
Learn lines as soon as the script is ready, this can waste precious time on set. Small groups in a class situation is ideal. Rehearsals and blocking can also be done before filming starts, and if the camera crew know all the action they can take responsibility for how shots are composed.
Rehearsals are still useful even if you're interviewing class members. Get them to write out and practice what they are going to say, but for actual rehearse use different question, to get them used to speaking in front of camera, but so they are not parrot-like for their actual interview.
Some of your group may be unhappy to be in front of the camera - be attuned of the politics.
If convenient, actors who are not in shot should stay in their positions to help those who are performing to look in the right direction.
If your team is small, actors can also be involved with filmmaking process, but they need to be clear which role they are doing at which time.