I would not recommend sniping to a new player AT ALL. It is expensive and very difficult, both because it's not easy to hit most targets at most ranges and because it gets very boring very fast. You gain 0 advantage as a sniper since any aeg will have the same range as you except youre stuck in bolt action with a maximum 30 round mag while they have semi, burst, and full auto as well as access to 120 round midcaps up to 4000 round drum mags.
To change fps, change the spring or barrel length. To change rate of fire, change the motor or the battery.