How to get to Ikebukuro from T2 Tokyo Narita Airport? Where can I buy a ticket?

It's good to take a bus from Ikebukuro to Narita Airport. First of all, you should go to Ikebukuro to find a way to take the Lokmachi line directly from Ikebukuro (or it's not far to walk to Ikebukuro anyway), and then you can wait for JR's N'EX in Ikebukuro or take the mountain people to Beijing at dusk (the green and red labels on it are the guide for the first and second terminals). As for the map you gave, it doesn't make much sense, because the tram from downtown to the airport has only two stops at the airport: Narita Terminal 2 and Terminal 1, so you just need to take the bus according to the ticket. In case you take the wrong terminal, I remember there is an internal contact tram at Narita Airport. You can take that bus to go back and forth quickly between the two terminals.