When you create a new feature or select an existing feature with the select tool you will see a popup allowing you to:
Save Feature
Delete Feature [only shown after first Save]
Undo changes [or Delete a New feature]
Enter feature name
Define feature Properties
Reshape
You can reshape your feature by hovering over a node until you see a hand and then dragging the node to a new location. If you wish to move the entire feature hover over the centre node to move it. With a Line or Polygon feature you may need to have a little look to find this.
Properties
Clicking the Properties button will allow you to change the specific properties for the selected feature only. See Layer Properties for details.
When you are happy with your feature click Save.
If you decide you want to make changes after your have clicked Save then pick the Select tool and click on your feature. This will enable editing.