1) Basic Corona concepts
This section contains the basic concepts of Corona programming, as variable, functions, logic operators etc. If you are a coder, you will be able to read that section really fast. If you aren't, I recommend you to read carefully to really understand the concept, since it will be the base for all your programming.
2) Display Objects and Groups in Corona:
This section explains how objects are displayed in the screen and their properties (position, color,...).
3) Events and Listeners:
Events are what the name says: Events. When you touch your device screen, you make an Event of touching. When you rotate your device, you made an Event of rotation. So, you can think of Event as predetermined actions that occurs with the device.
Listeners are functions that will take care of your event. As example, if you want the device to erase all data in the screen when the user shake the device, you need to have a listener that will be "listening" all events that are happening in the device and when it listens the event Shake, it will start running some codes that will erase the screen.
4) Physics module:
In the item #2 you will have learned how to display objects in the screen, but in gaming, you usually needs not only to display the object but enable it to interact with other objects. That interaction is made thru the Physics module.
5) Animations / Sprite Sheets:
Depending on which type of game you are developing, you will need to display images that have motion, like a player running or a bird flying. To make animations you will use Sprite sheets.
A Sprite sheet is a image file that contains several static images of your object, that if played sequentially it would make your object move. It is the basic technique of animation that we learned when we were children that we made several drawings with minor differences and then we passed thru the drawings very quickly and it would appear to be moving.
StoryBoard is a API that helps you to manage your application screens. It will allow you to have more control and facilitates the process of screen transitions. Although you can make the screen transitions without it, I highly recommend you to use it due to the facilitates of screen management that it will bring to you as your code gets bigger.
If you have any questions or doubts that these items, feel free to ask me thru the comments section.