Problemas com a instalação do grunt

Quando fui instalar o grunt apareceram essas mensagens:

1) Etapa do npm install -g grunt

npm WARN deprecated urix@0.1.0: Please see https://github.com/lydell/urix#deprecated
npm WARN deprecated resolve-url@0.2.1: https://github.com/lydell/resolve-url#deprecated

changed 213 packages, and audited 214 packages in 30s

6 packages are looking for funding
  run `npm fund` for details

found 0 vulnerabilities

2) Etapa do npm install -g grunt-cli

npm ERR! code EEXIST
npm ERR! path C:\Users\Lucas\AppData\Roaming\npm\grunt
npm ERR! EEXIST: file already exists
npm ERR! File exists: C:\Users\Lucas\AppData\Roaming\npm\grunt
npm ERR! Remove the existing file and try again, or run npm
npm ERR! with --force to overwrite files recklessly.

npm ERR! A complete log of this run can be found in:
npm ERR!     C:\Users\Lucas\AppData\Local\npm-cache\_logs\2021-04-13T01_20_42_661Z-debug.log

3) Na verificação da versão do Grunt

Command-line options: --verbose, --gruntfile=null

Reading "???" Gruntfile...ERROR
A valid Gruntfile could not be found. Please see the getting started guide for
more information on how to configure grunt: http://gruntjs.com/getting-started
Fatal error: Unable to find Gruntfile.

3) Etapa dos plugins do Grunt (aluras-Mac-mini:css alura$ sudo npm install grunt grunt-contrib-less grunt-contrib-watch jit-grunt --save-dev)

up to date, audited 263 packages in 6s

13 packages are looking for funding
  run `npm fund` for details

Gostaria de saber porque estão acontecendo esses erros? Quem puder ajudar agradeço.