Задачи по моделям и формам в django

class Authors(models.Model):
    male = 'm'
    female = 'f'
    sex_choises = [
        (male, 'm'),
        (female, 'f'),
    ]
    last_name = models.CharField(max_length=150, verbose_name='Фамилия')
    first_name = models.CharField(max_length=150, verbose_name='Имя')
    birthday = models.DateField(verbose_name='Дата рождения')
    biography = models.TextField(verbose_name='Биография', blank=True)
    photo = models.ImageField(upload_to='media/%Y_%m_%d', verbose_name='Фотография', null=True, blank=True)
    email = models.EmailField(verbose_name='Email', null=True, blank=True)
    sex = models.CharField(max_length=2, choices=sex_choises, default=male, verbose_name='Пол')
 
    def __str__(self):
        return f'Автор {self.last_name} {self.first_name}'
 
    class Meta:
        verbose_name = 'Автор'
        verbose_name_plural = 'Авторы'
 
 
class Books(models.Model):
    name = models.CharField(max_length=150, verbose_name='Название серии')
    author = models.ForeignKey('Authors', on_delete=models.PROTECT, verbose_name='Автор')
    couthor = models.ForeignKey('Authors', on_delete=models.PROTECT, verbose_name='Соавтор')
    date = models.DateField(verbose_name='Год выпуска')
    genre = models.ForeignKey('DirectoryGenre', on_delete=models.PROTECT, verbose_name='Жанр')
    serial = models.ForeignKey('DirectorySeriesName', on_delete=models.PROTECT, verbose_name='Серия книг')
    serial_number = models.IntegerField(verbose_name='Номер в серии')
    photo = models.ImageField(upload_to='photo/%Y_%m_%d', verbose_name='Фото книги', blank=True)
 
    def __str__(self):
        return self.name
 
    class Meta:
        verbose_name = 'Книга'
        verbose_name_plural = 'Книги'

my_book.author
my_book.coauthor

(<django.db.models.fields.BigAutoField: id>, <django.db.models.fields.CharField: name>, <django.db.models.fields.related.ForeignKey: author>, <django.db.models.fields.related.ForeignKey: coauthor>, <django.db.models.fields.DateField: d
ate>, <django.db.models.fields.related.ForeignKey: genre>, <django.db.models.fields.related.ForeignKey: serial>, <django.db.models.fields.IntegerField: serial_number>, <django.db.models.fields.files.ImageField: photo>)

{Field.name: Field}

class Form2(forms.Form):
    name = forms.CharField(label='Название книги', max_length=100)
    author = forms.CharField(label='Автор', max_length=100)
 
    def save(self):
        """самописный метод, вызывайте после вызова is_valid"""
        name = self.cleaned_data['name']
        author = self.cleaned_data['author']
        try:
            a = Authors.objects.get(last_name=author)
        except Authors.DoesNotFound:
            a = Authors(last_name=author)
            a.save()   # сохранили и получили id
        b = Books(name=name, author=a)
        b.save()

blank=True