How to tell if image formed by lens is larger or smaller, inverted or not by magnification?

Magnification = - p/s

So what if magnification = -0.2? Is that image BIGGER or SMALLER than the actual object? Is it inverted or not?

So basically what does the number 0.2 tell me? What does the negative symbol in front of 0.2 tell me?
ALSO, how do I know if it is upside down or not?

AND do convex mirrors ALWAYS form virtual images?