getting data from database in laravel using field from another table?

I create a delete function and it works but now when i delete i want to change the value of a column in another table can i get some help plz

  public function deletePark($id)
    {
        Parks::where('id', '=', $id)->delete();
        
        $response = array('response' => 'Park Deleted !', 'success' => true);
        return $response;

    }

and i try to do something like this but i get an error

 public function deletePark(Request $request,$id)
    {
        Parks::where('id', '=', $id)->delete();
        $model = new Parks();
        $var = Stocks::find( $model->Equipment = $request->Input('Equipment'));
        $var->park_id = 0;
        $var->save();

        
        $response = array('response' => 'Park Deleted !', 'success' => true);
        return $response;

    }

via Chebli Mohamed