Problemas com 'npm install'

Estou tentando criar um projeto Angular, e fiz o uso do seguinte comando para instalar o CLI:

npm install @angular/cli

Tive a seguinte saída no prompt:

npm WARN EBADENGINE Unsupported engine {
npm WARN EBADENGINE   package: '@angular/cli@11.1.4',
npm WARN EBADENGINE   required: { node: '>= 10.13.0', npm: '^6.11.0', yarn: '>= 1.13.0' },
npm WARN EBADENGINE   current: { node: 'v15.0.1', npm: '7.0.3' }
npm WARN EBADENGINE }
npm WARN EBADENGINE Unsupported engine {
npm WARN EBADENGINE   package: '@angular-devkit/architect@0.1101.4',
npm WARN EBADENGINE   required: { node: '>= 10.13.0', npm: '^6.11.0', yarn: '>= 1.13.0' },
npm WARN EBADENGINE   current: { node: 'v15.0.1', npm: '7.0.3' }
npm WARN EBADENGINE }
npm WARN EBADENGINE Unsupported engine {
npm WARN EBADENGINE   package: '@angular-devkit/core@11.1.4',
npm WARN EBADENGINE   required: { node: '>= 10.13.0', npm: '^6.11.0', yarn: '>= 1.13.0' },
npm WARN EBADENGINE   current: { node: 'v15.0.1', npm: '7.0.3' }
npm WARN EBADENGINE }
npm WARN EBADENGINE Unsupported engine {
npm WARN EBADENGINE   package: '@angular-devkit/schematics@11.1.4',
npm WARN EBADENGINE   required: { node: '>= 10.13.0', npm: '^6.11.0', yarn: '>= 1.13.0' },
npm WARN EBADENGINE   current: { node: 'v15.0.1', npm: '7.0.3' }
npm WARN EBADENGINE }
npm WARN EBADENGINE Unsupported engine {
npm WARN EBADENGINE   package: '@schematics/angular@11.1.4',
npm WARN EBADENGINE   required: { node: '>= 10.13.0', npm: '^6.11.0', yarn: '>= 1.13.0' },
npm WARN EBADENGINE   current: { node: 'v15.0.1', npm: '7.0.3' }
npm WARN EBADENGINE }
npm WARN EBADENGINE Unsupported engine {
npm WARN EBADENGINE   package: '@schematics/update@0.1101.4',
npm WARN EBADENGINE   required: { node: '>= 10.13.0', npm: '^6.11.0', yarn: '>= 1.13.0' },
npm WARN EBADENGINE   current: { node: 'v15.0.1', npm: '7.0.3' }
npm WARN EBADENGINE }
npm WARN deprecated har-validator@5.1.5: this library is no longer supported
npm WARN deprecated request@2.88.2: request has been deprecated, see https://github.com/request/request/issues/3142

added 236 packages, and audited 236 packages in 14s

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

found 0 vulnerabilities

Minhas perguntas são:

1- Como que eu crio o projeto angular? | 2- O angular-cli foi instalado corretamente? | 3- Falta alguma dependencia? | 4- Quanto tento usar 'ng new projetolegal', o cmd não reconhece o 'ng', faltou instalar alguma dependencia?