You will need to read the user guide, because there are some things that aren't obvious and you can pick up the terminology Cyberlink uses.
Chapters don't have return points except for the last chapter. Scenes (aka Titles), on the otherhand, have return points. What you have on the timeline is considered your first scene. You can import videos and other projects as "scenes." Scenes can have there own set of chapters. A scene could be a recording of a TV show episode, for example. To add more scenes to your project, click the "Create Disc" button, then the "Content" tab. There is a button to add videos and another button to add projects. This should update the menus automatically.
To delete menus, right-click on the menu thumbnail on the "menu preferences" tab, then select "delete from disc" from the pop-up menu.
Gateway DX4380, AMD A8-5500 Quad Core 3.2GHz with ATI Radeon HD 7560D; 16GB RAM; 1 TB SATA 7200 RPM; Windows 8 Pro 64-bit; PDR11, PDVD12.