JRPass.com is
not a JR official website.
(At the bottom of the webpage, you find a copyright claim saying "JRPass ltd."; how confusing!)
There is no process to "activate" a Japan Rail Pass.
When you turn in your Exchange Order for your Japan Rail Pass,
you set the day when you begin to use your pass,
then your pass should be valid from that day.
You cannot change the first day later.
In the list of the exchange offices on the official website,
you can confirm the following facts.
: In Central Japan International Airport there is Central Japan Travel Center which is handling Japan Rail Passes and open from 9:00.
: In Nagoya Station there are two offices of JR Tokai Tours handling Japan Rail Passes.
: One of the two offices (whose name is not Hirokoji Entrance Office) is open from 9:00.
http://japanrailpass.net/en/exchange.htmlOur flight is arriving at 7.30am at Central Japan International Airport, Nagoya This airport is actually outside Nagoya City.
When everything goes smoothly, you will get to (JR) Nagoya Station around 8:45,
so you can visit the JR Ticket Office, which handles JRP until 10:00 and after 19:00,
or the JR Tokai Tours office which is open from 9:00.
Both the two offices are along Central Walkway.
http://english.jr-central.co.jp/info/station/_img/nagoya_L.jpghttp://japanrailpass.net/img/purchase/file/exchange_station.pdfJR Tokai Tours is a subsidiary company of JR Central [Central Japan Railway Company].
(Also JTB finances this company.)
This travel agency not only sells tour packages but also issues JR tickets.
Once I have the pass and activated, can I reserve seats at both offices? Yes; you can try to reserve seats in JR trains at the same counter.
I recommend that you in advance write down on a piece of paper your itinerary (with timeline) which shows places to visit by JR, and show it to the staff of the office when you receive your Japan Rail Pass.
I understand that we have to make our own way to Nagoya station On your way from West Ticket Gate of Meitetsu Nagoya Station,
you first find Hirokoji Entrance of (JR) Nagoya Station,
then walk more to the JR Ticket Office | the JR Tokai Tours office.
It may need 15 minutes to go from the Meitetsu gate to the JR office.
You can make a shorter and simpler transfer from Meitetsu to JR in Kanayama Stations
(though you pay 170 yen per adult passenger for the JR section Kanayama -- Nagoya if you do without JRP).
http://english.jr-central.co.jp/info/station/_img/kanayama_L.jpg