The rules for Weyrlings are a bit more complicated than those for candidates, though they share many of the same rules.
1. No drinking. Period. Young dragons can mistake a drunken stupor for death, causing them to take themselves /between/ and leave you alone. Just say no.
2. No physical intimacy. Young dragons broadcast on a wide band. If you are intimate, everyone will know. This stricure will be lifted before the end of Weyrlinghood (generally after the mating flights lecture), your weyrling master will let you know.
3. You can't leave the Weyr until you've been taught to /between/ and your dragon can take you places.
4. No one without 'weyr' in their title (i.e. weyrling, weyrwoman, weyrling master, etc.) should be in the barracks proper. Feel free to kick them out or complain if they are.