How do I fix building errors with Angular Material Components?

@import "~@angular/material/prebuilt-themes/indigo-pink.css";
add this in style.css

As per the example given here, you also need to export the material modules from your shared material module

https://material.angular.io/guide/getting-started#step-3-import-the-component-modules

import {MatButtonModule,
        MatCheckboxModule} from '@angular/material';
 @NgModule({
   imports: [MatButtonModule, MatCheckboxModule],
   exports: [MatButtonModule, MatCheckboxModule]
 })
 export class MaterialModule { }