The Novice Researcher Bonus applies from the second sleep session after the tutorial until the seventh session.
You can only receive this bonus once a day.
Even if you record two sleep sessions on the same day, you'll only receive a bonus for the first one.
Additionally, even if you don't receive a bonus for a session, you'll keep receiving bonuses until you've received the seventh session bonus (600 points in total), so there's no need to worry.