3D Print gives you access to SelfCAD's slicer.
The first thing you will see after clicking 3D Print is the preview, where you can see the results of your operations. In the top part of the preview, there is one of the most important buttons in slicer - Slice. Only after pressing this button the object is sliced into layers and only then you can see how the object will look like, what the path of the nozzle will be, how long the printing process will take.
Navigation is a little bit different than in the SelfCAD app - you also rotate the camera using the left mouse button, zoom in and out with the mouse wheel, but to pan, you have to use the right mouse button instead of the middle one. You can also reset the camera by pressing the button in the bottom left corner.
a) What will happen if I put more than one object in the slicer?
The Slicer will ask you it should treat the objects as separate or not.
b) What if I can't find my printer in the Slicer?
You can create your own printer profile by pressing the 'Open Profile Editor' button. You can set all default parameters of your printer and material you use there.
c) Can I save the GCode?
After pressing Slice you can save the GCode, a file that provides information about the object being printed to the printer. When your object is sliced, the new button appears in the bottom right corner. The white text "Save GCode" on it suggests that it is this button that generates the file, which should be delivered to the printer.
d) What do I need to do to print my model?
To print your model you have to do 3 things: import the object into the slicer, slice it and save the GCode which says the printer what it should do.