started with the model

backend/secfit/challenges/admin.py

+from django.contrib import admin
+
+# Register your models here.

backend/secfit/challenges/apps.py

+from django.apps import AppConfig
+
+
+class ChallengesConfig(AppConfig):
+    name = 'challenges'

backend/secfit/challenges/models.py

+"""Contains the models for the challenges Django application. Coaches
+can create challenges for a group of athletes or individuals.
+"""
+from django.db import models
+from django.contrib.auth import get_user_model
+
+from backend.secfit.users.models import User
+
+
+# Create your models here.
+class Challenge(models.Model):
+    """Django model for a challenge.
+
+    Attributes:
+        name:        Name of the challenge
+        description: Notes about the meal
+        owner:       User that logged the meal
+    """
+
+    name = models.CharField(max_length=100)
+    description = models.TextField()
+    owner = models.ForeignKey(
+        get_user_model(), on_delete=models.CASCADE, related_name="meals"
+    )
+
+
+# class ChallengeInstance(models.Model):
+#     """Django model for an instance of a challenge.
+
+#     Each challenge has one or multiple user 
+
+#     Attributes:
+#         challenge:    The challenge
+#         user:   The user connected to the challenge
+#     """
+
+#     challenge = models.ForeignKey(
+#         Challenge, on_delete=models.CASCADE, related_name="users_instances"
+#     )
+#     user = models.ForeignKey(
+#         User, on_delete=models.CASCADE, related_name="instances"
+#     )
+
+

backend/secfit/challenges/tests.py

+from django.test import TestCase
+
+# Create your tests here.

backend/secfit/challenges/views.py

+from django.shortcuts import render
+
+# Create your views here.