Best meeting point at Narita

My friend arrives in Terminal 1 from Thailand I arrive Terminal 2 from the USA, I assume we have diffrent immigration and luggage pick up. Where could we meet? We arrive within 30 min from each other,thank you

Will you be needing to exchange a Railpass? In that case I would have the first one queue at the exchange counter, if necessary, otherwise wait in front of it (note that you will need both vouchers and passports).

Leaving by Skyliner? Then meet at the Keisei-Gate.
Leaving by NEX? Meet at the JR-Gates.

There is WiFi at the airport so if something goes wrong you can text each other in any case :)

Stupid me, I kind of missed the fact that you arrive at different terminals.
In this case I would have the first one to arrive change the terminal and meet at the points described above.

If you don't need to exchange RPs, an option would be to just get on the same train (JR or Keisei) at your respective terminals. This would take some coordination via messenger but is what I would do.

Keep in mind that reservations on Skyliner and NEX are mandatory so you most probably will not sit together.

My personal preference would for you to meet at the south wing arrivals point at terminal 1. While it is only a few minutes by train between the two, getting to the train, waiting and then to the arrivals point might take 20-30 minutes.
Also, meeting at T1 means for your trip into the city you will be boarding at the first stop which is much nicer than the mess I witnessed at T2 yesterday.

I think that @JapanCustomTours has offered the best solution and one that lets you sit next to each other on the train to Tokyo as well.

The best solution without extra cost could be below:

You: After clearing the immigration at T2, take a free shuttle bus to T1. (around 10 minutes from T2 to T1)
Your friend: Wait for you near the bus stop No.6 of T1, where the free shuttle buses arrive and depart.

Together: Take the train to Tokyo from the train station of T1.

As far as know, all trains from Narita Airport depart from T1, it'll be much easier to get seats together with your friend if you get on from T1. I've took trains from that of T2 many times, but I often find that a train gets already crowded because it gets enough passengers first at T1.

Will you all be staying in the same hotel? If you are, why don't you meet at the hotel? Your flight, or your friends' flight could be delayed. The waiting could be unnecessary, especially after a long flight.

Yes, there is the free shuttle bus - I did not suggest it as I hardly ever use it and probably the last time was around eight years ago - it's not a bad service, but the cost to get between terminals is pretty low. Given the OP will be using the trains, finding bus stops was just an additional complication (not a big one, but something extra.)