Missions and written answers only a person can judge. Quizzes mark themselves.
A first name is enough. Children don't get an account or an email.
You'll get a join code you can share with the class.
One name per line. Paste a whole class list if you like.
For a lesson the class watched together, on the board or offline. It counts towards their progress and certificate, and the certificate says how many lessons a teacher marked.