I have these lines on my old laptop. It began with one line and now I have several. There doesn't seem to be much support on the web about this issue (although it is a common issue).
It is likely that the connection between your laptops parts and your laptops monitor isn't great, it may be a little loose.
Considering you do not know too much with computers, I would recommend getting somebody you trust to open up your laptop and sort this out for you (it only needs the wire to be pushed in firmly- probably).
You could take it to a repair shop but it is more than likely that they will say your screen is broken and they will recommend you replace it, try my suggestion first.
Also, by wiggle the screen, he meant physically move the screen (as if you were closing the laptop or opening it) at certain angles, the line may go