Congratulations on your new puppy!
I definitely think it's best that your pup is in an exercise pen or crate until he gets bigger and has more control of his bladder. I would keep food out for him so that he has access to it for a while. Nutrical is definitely a great idea for a pup that little... You don't want his blood sugar to be low!
It sounds like you are very prepared for your new little guy
I can't wait to see pictures!