Once you have created a new field, you add the new field to a form. An easy way to do this is in Layout View. This view is only available if you have a form or a report open.
In Layout view, you can drag a field from the Field List pane to your form. You can also move the new field to where you want it by clicking and dragging the field name. Click Play to see an animated example of how a new field is added to a form.
You'll need to save your changes again.