Arrive Narita, same day travel to Nagoya Oct

I arrive at 8.30 AM and wish to travel to Nagoya on the same day. I am unsure on how long it takes to clear customs and catch NEX to Tokyo? From there wish to catch the Shinkansen to Nagoya but cannot find where to buy tickets outside of Japan prior to arriving.
JR Rail East site states tickets must be picked up the evening before but I have not arrived as yet.
Also if i do book online which time train to reserve seats on as I need to clarify travel time from Narita to Tokyo rail Station.
Also after F1 on the Monday return to Tokyo, this is a public holiday do trains have a restricted schedule on holidays?

Wait till you arrive in Japan - you clear immigration, customs, then follow the signs downstairs to the train station area of Narita Airport. You go to the JR ticket counter and ask for Narita Express into Tokyo, then onto Nagoya. They will get you the best ticket combination for that.

Thank You AK, good news

If you are coming for the F1 race weekend, then be prepared for slow/crowded travel between Nagoya (or any place in the vicinity where people stay overnight to the race) and the race track.

For the way back on Monday, no, it is not grestrictedh just because it is a holiday – railways have weekend/holiday timetable which is different from that for weekdays but doesnft mean far less trains or anything – just give yourself plenty of time for the travel from the racetrack to the station.

I did the same last year - arrived around 8:30am at Narita and I was able to catch some NEX which departed around 10:50 with quite a big time reserve. Then I rode 12:30 shinkansen to Nagoya. It might be good idea to get shinkansen tickets at Narita (Tokyo station is huge and can be confusing to navigate through).

Thanks for the helpful responses, I now feel more comfortable about getting tickets upon my arrival.

To clear customs count on an hour and get N'Ex tickets on arrival.

For the onward to Nagoya on Hikari (rail pass) you might need to get 2nd choice train - Nozomi services are better and have better availability. My experience over the last few years is that rail-pass trains are getting more full/sold-out and even tomorrow I am on my second choice train with my group (Tokyo-Kyoto on a non-busy day). JRP might save money, but cost more in time due to inflexibility - depends on the route.

And in OPs case it would depend on where they are traveling long distance to outside of their Narita to Tokyo to Nagoya travel.

If OP's trip to Japan is under 14 days they can get this special NEX round trip ticket at Narita for 4000 yen.
https://www.jreast.co.jp/e/pass/nex_round.html?src=gnavi

They would then just have their round trip to/from Tokyo to Nagoya which is ~20,000 yen. It might not be worth it to buy a rail pass.

I'm a party of two so as of last Summer, I had no problem booking hikaris I wanted between Tokyo to Kyoto or Osaka with a rail pass, but I have had a hard time booking a Sakura between Hiroshima and Shin-Osaka. In that case since the only non-sold out train was after 19:00, I just used a non-reserved car. But I'm only a party of two so finding seats is much easier than if I was a larger group.