Tbh, the way I level up is to play operation locker conquest large running assault with the aek or support with any carbine or lmg which ever your comfortable using throwing med kits down or ammo crates its a nice way to get points along with getting kill and playing the objective and always put on 25% or 50% xp boosts when playing and when your close to a medal if you have any 100 or 200% boosts equip them to maximize point gain.

Hope this helped you in finding out a new strategy to leveling up quicker.