Within the Manual you have a Turtorialscenario. The Turtorialscenario can be played by the Peg Original Installer.
Please start the Peoples General 1.o exe to play the turtorial
The Mods has the same rules as the original installer. But there are some differences. For Exemple, Tanks in the Napoleonic mod are Horses. Its the same for other mods around this timeperiode.
campaigns are very hard or almost unplayable. To win them sometimes is
the only way to modify a savegamevia Peg suite. You can make your units
stronger or clone them to have more units. You can also bring your
units near to the victory hex or remove some enemys.
Here you can download the tool : Peg-suite
For the mods before 1900 the gunsound is a bit nervekilling for my taste. You can use this one alternativ. Put it into the games wavefolder and replace the existing on.