Here's what things generally look like when you're working in the VB editor. As you can see, the IDE provides an embarassment of riches when it comes to windows:
The windows you see here are (clockwise from upper left):
There are more, lots more, but that's enough to confuse me, so we'll stop here for now.
Here's a general rundown:
VB considers the code contained in each presentation to be a project.
The Project Explorer window shows you a list of all the currently open projects (that is, PowerPoint presentations, whether they contain code or not).
You can doubleclick the name of the project or click the + icon next to the name to open the project in the Project Explorer window. You'll see folders representing the Modules, Class Modules, References and other bits that make up a project.
You can doubleclick a folder to see the individual modules or other items that it contains.
You can doubleclick a module, userform or other item to view it or the code it contains.
You can get confused by all of this. And you will. Don't worry. It'll pass.
Click Next to learn more about each of the different windows.