How to customize django admin user panel with model

def registration(request):
    project_code = request.session['project_code']
    if request.POST:
        user_form = UserForm(request.POST)
        vendor_form = UserDetailsForm(request.POST, request.FILES)
        print vendor_form
        if user_form.is_valid() and vendor_form.is_valid():
                if(User.objects.filter(username = user_form.cleaned_data['username']).exists()):
                    messages.warning(request, 'username already exists with same name')
                    return render(request, 'registration.html', {'user_form': user_form, 'vendor_form': vendor_form})

                if (User.objects.filter(email=user_form.cleaned_data['email']).exists()):
                    messages.warning(request, 'Email already exists with same email')
                    return render(request, 'registration.html', {'user_form': user_form, 'vendor_form': vendor_form})
                obj = user_form.save()
                vendor = UserDetails()
                vendor.user_id = obj.id
                vendor.address= vendor_form.cleaned_data['address']
                vendor.contact = vendor_form.cleaned_data['contact']
                vendor.dob = vendor_form.cleaned_data['dob']
                vendor.profile_pic = vendor_form.cleaned_data['profile_pic']
                vendor.video = vendor_form.cleaned_data['video']
                vendor.age = vendor_form.cleaned_data['age']
                vendor.city = vendor_form.cleaned_data['city']
                vendor.profession = vendor_form.cleaned_data['profession']
                vendor.country = vendor_form.cleaned_data['country']
                vendor.gender = vendor_form.cleaned_data['gender']
                vendor.language = vendor_form.cleaned_data['language']
                vendor.education = vendor_form.cleaned_data['education']
                vendor.project_code = project_code
                vendor.domain = 'admin'
                val = UserDetails.objects.filter(contact=vendor.contact, project_code=project_code)
                vendor.save()
                messages.warning(request, 'User  added successfully')
                return redirect('screencultures:home')
        else:
            messages.warning(request, 'Please enter Valid username and emailid')
            return render(request, 'registration.html', {'user_form': user_form, 'vendor_form': vendor_form ,'id': id, 'project_code' : project_code })
    else:
        user_form = UserForm()
        vendor_form = UserDetailsForm()
        return render(request, 'registration.html', {'user_form': user_form, 'vendor_form':vendor_form, 'id': id, 'project_code' : project_code})