所需的URL应为'.../journal/year/month'
Index.html

<a class="nav-link active " href="{% url 'journal' {{year}} {{month}} %}">Journal</a>

urls.py

urlpatterns =[
    path('', views.home, name='home'),
    path('journal/<int:year>/<str:month>/', views.journal, name='journal'),
]

Views.py

def home(request):
    year = datetime.datetime.now().year
    month = datetime.datetime.now().month
    return render(request, 'base/index.html',{
        'year': year,
        'month': month,
    })