Hi and WELCOME to YT, so glad you found us! Can't wait to see pics of Logan.
This thread will answer almost all of your questions:
http://www.yorkietalk.com/forums/pup...w-parents.html
And here is the Puppy Library for even more info:
Puppy Care and Puppy Info Library - YorkieTalk.com Forums - Yorkshire Terrier Community
More potty training info as yorkies can be tough:
http://www.yorkietalk.com/forums/gen...info-pics.html
And:
http://www.yorkietalk.com/forums/gen...ebreaking.html
Your breeder should tell you when, exactly, the next set of vaccines is due - they will also provide you with Logan's current vaccine record. At your next vet/vaccine appt - talk to the vet about the ideal age for neutering and concurrent retained baby teeth removal (you do this at the same time).
As far as travel, they should be able to travel with you right away - in the cabin. Many airlines allow this for an extra fee (not cheap).
As far as safety, just remember at first how tiny they are and that they don't realize how tiny they are...they also don't really understand heights at first, so you need to be very careful. Also, some people will put a collar on them when they're at home with a bell on it - so you know where they are and don't step on them.
On the subject of collars, don't leave a young puppy alone w/ their collar on! Also, yorkie are prone to tracheal collapse, so NEVER use a collar attached to a leash. Rather, you must buy a harness for putting him on a leash.
Hope some of this helps. Welcome again!