Saving a project?

I’m not quite sure how to save a project. I can import or drag and drop the clips into Shotcut but when I’m finished editing them how exactly do I save them. I tried Save As and it didn’t seem to work. Also, there’s this little bar above the timeline next to Source what’s that function?
Thanks in advance for any help or suggestions.

‘Saving’ = Saving the project file (*.MLT)
You need to ‘Export Video’…

Great, I did that. I exported it as a mp4 file but now when I try to add it to my Facebook page it doesn;t work. I keep getting an error message. Do I need to export it in another format?

Actually I’m pretty damn proud. I assembled my first little short video with a couple of fades.

I have no idea what you have done or what the FB error message is?
But I always use an mp4 preset for FB or YouTube. Never an issue.

So long as your video plays on the computer is should be fine for FB.