SOLUTION A
Go to Window > Galley & Story Appearance. Click on it. The font/size bar should be on the bottom left of the InCopy screen. (If it is already checked and the bar is not on the bottom left of the screen, go to Solution B)
Use the drop-down tool to select an appropriate font for screens (Arial, Helvetica, Times New Roman, Verdana etc. ) and size.
SOLUTION B
Go to Window > Galley & Story Appearance. Click on it again and again until you are able to locate where the bar is.
Once you've found it, click your mouse on the vertical column of dashes on the bar or the dark gray end of the bar , hold down, and drag it to the bottom left of the screen.