CHECKBOX_CHOICES = (('1', 'The first choice'), ('2', 'The Second Choice'))

class Order(models.Model):
        paid = models.CharField(max_length=350, choices=CHECKBOX_CHOICES)

from django import forms
from .models import Order

class OrderCreateForm(forms.ModelForm):
    class Meta:
        model = Order
        fields = ['paid']
 widgets = {
            'paid': forms.CheckboxSelectMultiple()
        }

<form action="." method="post" class="order-form">
    {{ form.as_ul }}
    <p><input type="submit" value="Submit"></p>
    {% csrf_token %}
  </form>

<ul id="id_paid">
    <li><label for="id_paid_0"><input type="checkbox" name="paid" value="" checked="" id="id_paid_0">
 ---------</label>
</li>
    <li><label for="id_paid_1"><input type="checkbox" name="paid" value="1" id="id_paid_1">
 The first choice</label>
</li>
    <li><label for="id_paid_2"><input type="checkbox" name="paid" value="2" id="id_paid_2">
 The Second Choice</label>
</li>
</ul>