Use the "Zoom In" tool and click on the stadium.

Click "Add Point" tool and click in the center of the stadium.

In the popup window, click the "From Map Canvas" button. and click on the center of the stadium on the modern map. \
Click "OK".

Tips!

If you lose your georeferencing window, it minimizes to the bottom right. Click on the expand to open it again.

If you accidentally click the wrong location, go back to the georeferencer popup and click "From Map Canvas" to try again.

The final points should like like this on both maps.

QGIS Georeferencing Tutorial 5: Find your First GCP Point