Create 'core' app

core/admin.py

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

core/apps.py

+from django.apps import AppConfig
+
+
+class CoreConfig(AppConfig):
+    default_auto_field = 'django.db.models.BigAutoField'
+    name = 'core'

core/models.py

+from django.db import models
+
+# Create your models here.

core/templates/index.html

+Initial index page

core/tests.py

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

core/urls.py

+from django.urls import path
+from . import views
+
+urlpatterns = [
+    path('', views.index)
+]
+

core/views.py

+from django.shortcuts import render
+
+# Create your views here.
+def index(request):
+    return render(request, 'index.html')
+

topgym/settings.py

@@ -42,6 +42,7 @@ INSTALLED_APPS = [
     'django.contrib.sessions',
     'django.contrib.messages',
     'django.contrib.staticfiles',
+    'core'
 ]
 
 MIDDLEWARE = [

topgym/urls.py

@@ -14,8 +14,9 @@ Including another URLconf
     2. Add a URL to urlpatterns:  path('blog/', include('blog.urls'))
 """
 from django.contrib import admin
-from django.urls import path
+from django.urls import path, include
 
 urlpatterns = [
     path('admin/', admin.site.urls),
+    path('', include("core.urls"))
 ]