A few questions about logging 121 time:

How do you separate rows in your paper logbook? A new row for each leg? Each aircraft? Each flight number?

When listing Aircraft ID do you use the flight number or N-number?

Also, I have some level d sim hours from the 121 training, was I supposed to log those in my personal logbook? instructor never mentioned anything about it, but from viewing this site it looks like i should/could have.

Thanks!