@Sassy Hi. In animation you aren’t allowed to have separate projection speeds. We depend on animating always to a target projection rate depending on the broadcasting channel (e.g TV, Web, Games, etc)
As such you are meant to always set a target framerate (e.g 24FPS for film, sometimes webseries, 30 fps for NTSC TV, 60FPS for games, etc)
And animate your actions always constrained to those limitations. Even youtube have “standards” for this.
To make the animation “feel” faster you have to use less drawings in the same amount of time, and to make them slower you have to use more drawings.
A practical example is: Let’s say you have a kitten that walks from left to right of the screen. You want it to cross the screen doing several antics in less than 4 seconds.
4 seconds at 24 fps is 96 frames in total. This means you have 96 possible drawings to allocate your animation and character actions.
Lets say that in those 96 frames you want the kitten to walk stealthily, anticipate a pounce, and lounge towards something (maybe food) outside the right border of the screen.
By experience and observation you determine that the cat needs about 48 frames (2 seconds, slow action) to walk stealthily towards about half of the screen. Then the kitten stops and prepares to pounce for about 36 frames (1 1/2 seconds, slow action and lastly the pounce will have 12 frames left (fast action) out of the total 96 to represent the kitten moving outside of the screen.
This is how you have to make things faster or slower in traditional animation.
With that said there are particular functions in video editors that allow you to slow down or fasten a “clip” of video. If you make a slow clip (more drawings) become fast, you will lose drawings. And if you make a fast clip (less drawings) become fast, this is where you need commercial grade software that “tries” to fill frames to make it feel slower by inserting similar drawings next to the original ones.
However these functions also work assuming that you can only use a single target projection rate, so regardless of method you are not’ meant to change this at will; choose one based on where you want to showcase your work.
I hope this explanation is in-depth enough to help you with your endeavors.