Hey Siddharta, ah ok so the Stagg acoustic guitar with a pickup (great starter guitar by the way). Yes, that is considered an acoustic guitar (even though technically it can be plugged into an amp), so your playing style on that guitar would be no different than playing on an acoustic guitar with no pickup.
As for your second question, usually they are separate because they handle tones very differently, although there’s nothing stopping you from plugging your Stagg acoustic into a regular electric guitar amplifier (that’s what I usually do), I’ve never bought an actual acoustic amp - although I do love the way they sound.
-brian