this is my package.json file:
{
  "name": "martina",
  "version": "1.0.0",
  "description": "d",
  "main": "index.js",
  "scripts": {
    "start": "node index.js",
    "test": "echo \"Error: no test specified\" && exit 1"
  },
  "repository": {
    "type": "git",
    "url": "d"
  },
  "author": "",
  "license": "ISC"
}
what should I do? I have a Mac by the way!
EDIT: I did what you guys recommended and added the script start, but now when I run 'npm start' I get this:
> martina@1.0.0 start /Users/martina
> node index.js
internal/modules/cjs/loader.js:589
    throw err;
    ^
Error: Cannot find module '/Users/martina/index.js'
    at Function.Module._resolveFilename (internal/modules/cjs/loader.js:587:15)
    at Function.Module._load (internal/modules/cjs/loader.js:513:25)
    at Function.Module.runMain (internal/modules/cjs/loader.js:760:12)
    at startup (internal/bootstrap/node.js:303:19)
    at bootstrapNodeJSCore (internal/bootstrap/node.js:872:3)
npm ERR! code ELIFECYCLE
npm ERR! errno 1
npm ERR! martina@1.0.0 start: `node index.js`
npm ERR! Exit status 1
npm ERR! 
npm ERR! Failed at the martina@1.0.0 start script.
npm ERR! This is probably not a problem with npm. There is likely additional logging output above.
npm WARN Local package.json exists, but node_modules missing, did you mean to install?
npm ERR! A complete log of this run can be found in:
npm ERR!     /Users/martina/.npm/_logs/2020-06-11T08_05_28_654Z-debug.log
 
     
     
    