Better than the manual at explaining what the AF settings of the cameras are and the difference between them, but I have yet to find a tutorial on how to use AI Servo successfully

For one thing, without the red focus point lighting up, it's pretty much useless or how else does one know which point is in focus?
This tip:
"With “AI Servo AF” mode, the shooting starts
from one AF frame that is optionally selected.
So select one of any frames covering the
position where object capturing starts. In
addition, it will be easy to continue tracking
thence very convenient, if the same start
position is selected for Single Point AF and
then AF area is switched to 61 Point
Automatic Selection AF."
How does one switch both from Single Point AF to 61 Automatic Selection AF with one button click?
Thanks
ET