I inserted a CD into my lenovo laptop.Nothing changed on my screen.Now what?

Windows key and e at same time, click on cd

Anything you like! Depends what you want to do with the CD.

Don't know

Autoplay is not set to "Ask every time" or Autoplay is disabled or the CD drive may not be working

Not going to type all this again.

PS… ( You did not list your operating system or what type of CD? )
for the Manual method in the above link
Click "Computer (Windows 7 & vista).
Click "My PC" (windows 8)
Click " This PC windows 8.1 & 10 ) .