Getting a Welcome SUICA or Pasmo Passport will be recommendable

It is very convenient to have an IC card to get around the Tokyo Metropolitan area.  

Because of the lack of IC chips, you can only get Welcome Suica-s at the airports now.

​Welcome Suica | JR-EAST (jreast.co.jp)

Unless you're a person who can get used to using a lot of different coins, the IC cards will save you becoming coin collectors.  You can use them at many vending machines with oval marks of PASMO/SUICA and also at convenience stores nationwide.

Also most of the transportation, you can board by tapping the oval at the ticket gates when you get in and out.

You can also get the Pasmo Passport with this cute Sanrio design with 1500 yen if you present passport to prove you're  temporary visitors.

​Getting a PASMO PASSPORT｜ PASMO PASSPORT / PASMO​

There is also an option to add either to your Apple Wallet.

​Add a Suica, PASMO, or ICOCA card to Apple Wallet - Apple Support

You won't need a physical card in that case but you need "an eligible payment card in Apple Wallet."

That means, you need to have an American Express or Master card tied to the Apple Wallet.

They will save you a lot of trouble and you won't need to buy tickets each time you board.  Good luck!!