You will enjoy this game much more if you just forget there is even a score.
This.
Score is useless, only thing you need to learn is how the Perk modifier system works, I love perks - even though I only use em to crash 262s drunk trying to deack airfields etc.
I normally don't perk farm if the Modifier is below .80, I try to stay above .85 or 1.00.
System is quite basic:
If the modifier says 1.00 then you get 100% of the perks, more players you have on vs other countries, the modifier will drop... for example if the modifier is .50 and you are in a P51 and shoot down a p51 you get HALF a perk, if the modifier is 1.00 you get 1 perk.
I specifically hunt 5 eny planes when I am in a 25/30 eny aircraft, that yields 5 or 6 perks per kill, although you don't always get to choose what you fight, most of the time you run into lower eny planes

Like yesterday, I took up a Ki-61 and shot down 3 CV planes, was not happy I only yielded 3 perks