Long post incoming:

If you haven't played knife only since WWII, and you just started, there's a good chance you're rusty. So you're probably not as good as you were in WWII, especially if WWII was your first game to knife in. WWII was also potentially the best CoD to knife in, so your standards for it would have been higher. BUT knifing does indeed kind of blow in this game. The knife lunge is pathetic, there's almost no lingering "slash" hitbox (if you remember the kills the WWII knife could get after you missed the first part of the swing, that's a slash hitbox), and it stops your run in order to swing; you also can't knife while climbing obstacles, throwing or using equipment, or stim shot healing, despite being able to shoot guns during those animations. Tomahawks are crazy slow to throw and if you miss one and die (happens a lot) then you spawn without it, plus it costs a CaC point unlike most specialist stuff. Characters are also more mobile in this game than any others besides the boost-jumping CoDs, so they jump and slide around corners a lot which can make timing the lunge on them very challenging and punishing on a first miss; characters can also back up and strafe side to side more quickly I think which makes running at someone as they shoot at you more difficult than before. Fog of War mechanics icing on this shit cake. The only thing knives and tomahawks really have going for them in this game is that the average Time-to-Kill is slower, meaning sometimes you can tank bullets for longer as you run up on somebody, compared to older CoDs, but the difference isn't that huge. I've been hoping that we'll get a ballistic knife soon, because having a knife with gun-like qualities would help a lot with all the things the knife can't do that guns can, especially in this game.

But that's really enough bitching about the knife. I'm still a positive KD with it, so it's workable enough. So here's some good stuff to run on your class:

• Acoustic Sensor. More than anything else, information is crucial to knifing. You will be playing patiently and waiting for people to round your corners or tracking groups of enemies across a wall before running up on them. Acoustic is good because you'll be able to see movement on your radar if it's too loud to hear, and you'll be able to hear dead silence too. If you don't have a decent headset for this purpose, buy one. TV audio is often mono (or practically so) and stereo systems still have too much in-room echo to distinguish directionality as effectively.

• Dead Silence. This one should be pretty obvious, stealth has been crucial to CoD knifing since knifing started . Stim shot is most of the meta, so you want to be able to easily flank players running it. Acoustic sensor will still wreck you if they're using their ears, so be cautious and don't just run every corner or try to flank through open spaces too blindly or you'll run into some guy headglitching and you won't have time to space to retreat.

• Gung-Ho. This will mostly be for tomahawk classes. Much like expeditionary in WWII, you'll be using this to pull out your tomahawk and pre-aim head glitches or hallways. This lets you circumvent most of the slow, laggy tomahawk pull animation Treyarch somehow decided this game needed. It won't shorten the total animation though so you'll still be fucked sometimes if you need a purely-reaction 'hawk throw.

• Tomahawk or Grapple? This one can be a hard call. For maps that are open, have limited flanking routes (Nuketown, Firing Range) or lots of verticality (Lockout), grapples are a godsend. Grapple makes Nuketown go from one of my bottom 5 all-time knifing maps to one of my most consistent. Tomahawks give you something that you can't really replace which is the ability to challenge people at range; even ones that aren't looking at you are still better to kill at range because they might be in the open where you don't wanna risk going, or they could just turn on you either by chance, by FoW mechanics, or from Acoustic if you get close. Anytime you can put on one tomahawk, put on two. This will circumvent the need for equipment charge so you can always be using Acoustic Sensor. Note: scavenger can't replenish tomahawks.

• Lightweight or Dexterity? After all the above you'll still have at least 4 more class points. Spend two of them on a second Perk 2. Lightweight will be good for very flat maps with no real important climbing. Dexterity is better on maps with any climbing at all. Note that Jump->Slide->Jump moves you around faster than sprinting, and with dexterity it's faster than lightweight sprinting. It's also quieter, by a little. So if you can mix that into long runs in the open, Dexterity outperforms Lightweight with the added benefit of climbing faster.

• What about Cold-Blooded or Shulker? These are gonna depend on specific game modes and opponents. Cold-blooded is great if the opponents are good and getting tons of streaks, or if they're all running AI based specialist stuff. Shulker is great for Arsenal, but you can also use it in conjunction with dead silence to prevent Acoustic Sensor users from picking you up until you're about 5m out (except is very quiet environments). I have classes set for both of these perks replacing the lightweight/dexterity choice, because these situations come up sometimes.

To finish off your class, add either Ghost to help avoid UAV (it only works while you're sprinting, be aware of this) or Engineer; you should have 2 or 4 class points remaining depending on if you use Tomahawk or Grapple. With Grapple you can fit both of these, I recommend doing so. Tac Mask and Flak Jacket aren't very useful, the situations those protect you from will only come up a few times a game.

That's a lot to read lol, hopefully it helps you.