In the bottom centre of the screen you will see a tip giving you an indication of what Codesign is expecting you to do next.
Note: In many instances there are many things you could do so at this stage the tip focuses on the most likely action.
In some cases you can expand the tool tip (with the yellow arrow) and further help and a small movie will provide more information.
Use the X on the Tool tip to close the tips.
If you want to re-enable the Tool tips you can turn these on in App Settings.
You can also Hide / Show these tips via the Support menu: