Not the sort of question you ask on an online game forum, even more so on F2P.
What you should be asking is if not getting kills is normal in this game, which it is most definitely.
I have rarely played a game - since 1982 - where getting a confirmed kill is so difficult, although I have somehow got 5 in 10 levels.
The knock down system is the problem, you take them down then on top of that you have to get them again. Fine if it is 1-1, but if there is their team you have no time and if you have your team it usually gets stolen.
Even when they are down a machine gun doesn't seem to do much to them, especially with a shield, and someone steals your kill.
The guns are trash and it is usually all close quarters fighting where bunnyhopping and strafing > aiming.
To be honest - I rarely hit anything at all while I am playing.
It is one of those games where if guns were as dangerous in real life as they are here you would be better off with a stick or a rock.
And the way to tell if a player is legitimate or not and you can see if their k/d ratio is how high it is.
If it is under 100 they are normal and playing as everyone else is, if it is over 100 then something is awry and if it is heading to 1000 or above - 4000 maybe - then give them applause for the 'coding assistance' they are getting away with.
There is little gun play skill in this game, it does not have the design to be aim skill based, and even the punch is puny and does no damage.
So you have to choose whether you want to 'enjoy' the no damage, no skill guns or the actual experience, team play and cooperation.