npm install -g @angular/cli Then run the following command to create a new project. ng new foldername Now, get inside that folder using “cd foldername” and launch the server using ng serve.

A tag already exists with the provided branch name. Many Git commands accept both tag and branch names, so creating this branch may cause unexpected behavior. Are you sure you want to create this ...

Yeah this error isn't with Angular CLI itself but with npm. You seem to be getting integrity checksum failed when using sha1 error that prevent you from installing packages.