npm can't find package.json

I think, npm init will create your missing package.json file. It works for me for the same case.

Update 2021

npm init

Please refer to Deepali's answer for details.

Original Outdated Answer

I think you forgot to setup the directory for express:

express <yourdirectory>

Once you do that you should be able to see a bunch of files, you should then run the command:

npm install -d

Regards.

I'll be brief but deadly. :) install -d will not work for you. It's simple. Try

$ npm install -g express

Follwing the below steps you well get package.json file.

npm --version
npm install express
npm init -y

If Googling "no such file or directory package.json" sent you here, then you might be using a very old version of Node.js

The following page has good instructions of how to easily install the latest stable on many Operating systems and distros:

https://github.com/joyent/node/wiki/Installing-Node.js-via-package-manager