what is the best way to get to ikebukuro ?

hi,this is my first time traveling to tokyo,
my fight will reach around 7.50am,i plan to purchase metro pass and collect my b mobile sim,i'm not sure if i'm able to catch the N'EX 8.53am,if i miss it,i might have to take n'ex 09.19am but alight at tokyo station or skyliner 9.18am and alight at nippori,for a newbies,which one is more easy ?
2- can a 843�~355�~575coin locker fit in 29inches luggage ?
Thank so much

A metro pass? If (yes, if) it's even worthwhile then you'd get it as part of a skyliner combo deal. A metro pass is only valid on metro lines of the subway, not Toei, and not JR.

If you catch the NEX, get the Suica package. I'd recommend a Suica regardless as they're very convenient.

2) Convert between metric and imperial measurements yourself and you'll know the answer.....

i have suica card so don't intend to get any package,will be just getting metro pass
heard that tokyo station is super big so might lost my way if i take n'ex,

A foreign visitor can travel from NRT to Ikebukuro for 1500 yen per adult with a N�fEX Tokyo Direct Ticket.
(Sale of Suica & N�fEX packages was discontinued in March 2014.)

When will you travel?
Which place around JR Ikebukuro Station will you head to?
Which areas in Tokyo will you visit using subway?

I might have to take N�fEX 09.19am but alight at Tokyo Station

You will not have to disembark in Tokyo Station, where the two platforms (of JR + JR / of JR + subway) are located horizontally apart.
Narita Express 10 will not bring you to Ikebukuro, but you can change trains at the same platform in Shibuya Station.
(If you cannot catch a later non-N�fEX train soon on the same Track 3 in Shibuya Station, you can walk via a pathway above the tracks to the platform for Track 1, and catch there a train on Yamanote Line�fs outer loop within 5 minutes.)

Airport Terminal 2 (09:19)
| [JR lines: Narita Express 10]
Track 3: (10:40) Shibuya (10:44 or 10:45): the same Track 3
| [JR Shonan-Shinjuku Line: Rapid]
Track 3: (10:55 or 10:56) Ikebukuro.

my fight will reach around 7.50am
I�fm not sure if I�fm able to catch the N'EX 8.53am,if I miss it, I might have to take N�fEX 09.19am

The mentioned two N�fEX trains are Narita Express 8 and Narita Express 10.
If everything goes smoothly, you might catch the former Narita Express 8.
And, unless your flight or immigration procedure happens to be delayed much, you can have enough time before catching the latter Narita Express 10.

Each of the two N�fEX trains is a two-destination train until reaching Tokyo Station, where it is divided into two parts. Shibuya Station, Shinjuku Station and Ikebukuro Station are beyond Tokyo Station when you take a N�fEX train.
Seats of a N�fEX train requires reservation.
JR East Travel Service Center in NRT Terminal 2 is not open until 09:30. You can visit a JR Ticket Office (located just beside the JR gate) instead.

I plan to purchase metro pass
or Skyliner 9.18am and alight at Nippori,

Please note that a Tokyo Metro Open Ticket in a Keisei Skyliner & Metro Pass package cannot be used on Toei subway lines (= Asakusa Line, Mita Line, Oedo Line, Shinjuku Line).
You can choose a Tokyo Subway Ticket, which can be used on both Tokyo Metro and Toei subway lines.
Whether a subway pass pays off or not depends on your destinations and traveling paces.

If you take Keisei Skyliner 4 + a JR train (with a simple transfer in Nippori via a transfer gate), logically you can reach JR Ikebukuro Station earlier by about 30 minutes compared to JR Narita Express 10 + a JR train.
However, even if you choose a one-way Keisei Skyliner & Metro Pass package you will pay at least 2165 yen per adult on the Keisei + JR route, while you can take the JR-only route for 1500 yen per adult if you choose a N�fEX Tokyo Direct ticket.

If you travel back to NRT by rail, a roundtrip Keisei Skyliner & Metro Pass package is worth considering. But, if you are OK to take trains back to NRT without seat reservation, you can do it for 1200 yen or less per adult, so you will not need the roundtrip package.