How do you verify the existence of the network card and types of it in the computer practically?

Every program you use has a menu of tools somewhere. In Windows it is the "START" icon. It is a menu of menus. Click on each menu and inspect all the items on it. You don't have to memorize everything, just remember where to find them. Do that in every program that you use, and then you can claim to know how to operate a computer at the beginner level.