Target Class Admin HomeController não existe Laravel 8
Route::get('/home', 'App\Http\Controllers\HomeController@index')->name('home');
Snippets
Route::get('/home', 'App\Http\Controllers\HomeController@index')->name('home');// Change in Http\Provider\RouteServiceProvider.php
public const HOME = '/home';
/*---------------------------*/
protected $namespace = 'App\Http\Controllers';