npm errors while trying to run json scripts on new laptop - node.js

Question

I did an online course about coding, which included a couple of small scripts to compile my sass and concat my css files. Recently I got a new laptop and I did install node, installed my dependencies but for some reason I can't get any of them to work.
Here is what I did:
Installed node (current version: v10.15.2)
Did npm install and:
* sudo npm install live-server -g
* npm install autoprefixer --save-dev
* npm install postcss-cli --save-dev
Here are my json scripts:
"scripts": {
"watch:sass": "node-sass sass/main.scss css/style.css -w",
"devserver": "live-server",
"start": "npm-run-all --parallel devserver watch:sass",
"compile:sass": "node-sass sass/main.scss css/style.comp.css",
"concat:css": "concat -o css/style.concat.css css/icon-font.css css/style.comp.css",
"prefix:css": "postcss --use autoprefixer -b 'last 10 versions' css/style.concat.css -o css/style.prefix.css",
"compress:css": "node-sass css/style.prefix.css css/style.css --output-style compressed",
"build:css": "npm-run-all compile:sass concat:css prefix:css compress:css"
},
Here I my errors:
` npm start
> talentsfestivals#1.0.0 start /Users/vasil.krumov/Documents/Projects/TalentsFestivals
> npm-run-all --parallel devserver watch:sass
internal/modules/cjs/loader.js:583
throw err;
^
Error: Cannot find module '../common/bootstrap'
at Function.Module._resolveFilename (internal/modules/cjs/loader.js:581:15)
at Function.Module._load (internal/modules/cjs/loader.js:507:25)
at Module.require (internal/modules/cjs/loader.js:637:17)
at require (internal/modules/cjs/helpers.js:22:18)
at Object.<anonymous> (/Users/vasil.krumov/Documents/Projects/TalentsFestivals/node_modules/.bin/npm-run-all:13:1)
at Module._compile (internal/modules/cjs/loader.js:689:30)
at Object.Module._extensions..js (internal/modules/cjs/loader.js:700:10)
at Module.load (internal/modules/cjs/loader.js:599:32)
at tryModuleLoad (internal/modules/cjs/loader.js:538:12)
at Function.Module._load (internal/modules/cjs/loader.js:530:3)
npm ERR! code ELIFECYCLE
npm ERR! errno 1
npm ERR! talentsfestivals#1.0.0 start: `npm-run-all --parallel devserver watch:sass`
npm ERR! Exit status 1
npm ERR!
npm ERR! Failed at the talentsfestivals#1.0.0 start script.
npm ERR! This is probably not a problem with npm. There is likely additional logging output above.
npm ERR! A complete log of this run can be found in:
npm ERR! /Users/vasil.krumov/.npm/_logs/2019-03-03T15_29_19_750Z-debug.log `
Can anyone please help me?
Thanks so much in advance!

Answer 1

For the sake of others searching for the solution to your problem, i will write it here to make it easier to locate.
The first problem seemed to be some old modules, to clean it up remove you modules folder and npm install again.
The next problem seemed to be EACCES permissions errors. Usually you don't want to sudo install npm packages. If you have EACCES permissions errors look at this documentation