Why are some lines not connected when drawing with DXP? .

I'm a rookie, too. I was wrong. The prawns have to joke.

The first question: the colors of components are different, which means they are at different levels. It seems that your two diodes are either missing a pin or duplicated.

The second question: No matter what components are drawn, the pins should be added with "Add". You may have drawn pushpins yourself, but the software doesn't know.

The third question: this dotted line is not a wire, but a hint of connection. After the wire is deleted, the remaining part usually appears.

As for schematic diagram to PCB, this is the basic knowledge. It's a long story I wonder if you will build a project first, and then draw a schematic diagram in this project. If that's the case, then you only need to change it and you can go to PCB. Of course, the connection can go automatically, but most of them are hand-drawn.

Self-drawn components must be in the component library to be automatically updated.