FPS Cap

Fps in Bo2 matters GREATLY. Fps can cause the gravity in game to become wonky and make you have lower jumps affecting strafing and destroying regular mechanics of the game. The peak Fps of Bo2 is 60-90 Fps 60 being better but 90 is barely worse to the point where it's not even noticeable, 120 is still playable but not recomended and anything above 120 is awful DO NOT use it.

Weapon Speeds

Each weapon has a base speed which impacts how fast/far you are able to go within a certain amount of time. A lot of weapons a part of certain types of weapon groups i.e Pistols, Assault Rifles, Lmgs etc... share a lot of the same values, but some have very unique values and can become essential when trying to move faster. I will provide a chart of all the weapons and their category of movement speed (Top = Best, Lowest = Worst)

As you can see 3 weapons share the same value of 200 base velocity, which are the weapons you want to use the most when possible, 190 is also good but you want to avoid using anything under the 190 base velocity as they will make you extremely slower compared to other weapons, and impact your overall times and movement.

Ground Strafing

Is the action of moving left to right using W&A or W&D depending on if you are going left or right, and with your mouse making your camera movements gradually moving toward each Keystroke (W&A easing your camera movement left, W&D to the right). Using the M1911 with base movement speed of 190, you can easily get 310-335 velocity which is increasing the base run speed of the 1911 from 285 by 25-50 velocity.

Strafing

Is the action running and jumping while using your directional keys W&A or W/D depending on if you are going left or right. There are multiple factors that go into executing an effective strafe jump. When strafe jumping after you do the jump you want to make sure you hold W&A or W&D through the whole strafe (time in the air), this make it so you can keep gaining velocity while you are in the air. Also when strafe jumping you want to make sure your mouse movement isn't a flick but a smooth and fluid motion, flicking can make you seriously lose velocity. Ground strafing and regular strafing go hand in hand as you always want to ground strafe before you do an actual strafe as it increases the amount of velocity you can gain while in the air. Bhopping (jumping) at the 2 times as you hit the ground at the end of a strafe keeps some momentum and helps propell you forward and regains your stamina (You also have to use W&A or W&D for this). Finally doing a crouch while you are in the air can be cruicial for strafing as on certain maps it can help you avoid obstacles and bumping your head on objects making you tremendously lose speed. The ideal speeds to hit while strafing is minimum of 340+ velocity during a strafe. Watch this video as an example

Boosting

The action of boosting yourself with weapons such as the Boomhilda, Raygun Mk2 and Ballistic Knives. You propel yourself by shooting the opposite direction of where you want to go to boost yourself where you want to go while holding S. This makes you gain tremendous velocity in open areas, and make certain jumps that otherwise wouldn't be possible (like in the origins speedrun).

Wall Running

The process of holding W&A or W&D on a wall to increase your velocity. The wall has to be fairly straight with not a lot of things to block you. The angle you are looking also effects your velocity doing this. Doing this with a base velocity weapon of 190 you can get anywhere from 310-350 velocity depending on what angle you are looking, which is 25-65 more velocity than just sprinting. You want to look a very tiny bit toward the wall to get peak velocities while wall running. Here is a clip of it in action 

If you still are having trouble with movement here is a full movement guide video by JDubs: