With regard to your juggling KR, I learned by a method of breaking it down that I found very helpful and learned from a book that I can't remember the title of, and would like to relate here.

I learned in ~3 hours of low effort while watching TV during a single day, told a friend about it, and they subsequently did the same thing that same day. Afterward we both said things to each other like "wow, I had no idea it was this easy!"

A quick disclaimer: this is for 3-ball juggling. 4-ball is a bit different, and I have heard it is a better foundation for 5,6,7+, but I never learned how to do it well.

First, get your three balls or similar. Hacky sacks, tennis balls, bean bags, rubik's cubes, whatever you've got.

Second, sit somewhere comfy and safe, with your arms down and your hands roughly near your knees if they were crossed. Hold just one ball. Practice tossing that one ball from one hand to the other hand, tossing it to about eye level on each throw. Your goal here is to keep your hands mostly down and apart and to get used to the feel of what power of throw you need and where your hand needs to be to catch the ball, without spending too much attention watching your hands. Practice left to right repeatedly, and right to left repeatedly, and then also practice back and forth. This should take somewhere between 5 minutes and an hour total -- but try to make this easy. If a later step is hard, do this first step more. Make sure the ball gets right to about eye level on each throw, in a neat little arc.

Third, once you feel good about the above, sit in the same position, with one ball in each hand. Throw one and when it hits the peak, around eye level, throw the other, and then catch them both. That's it. Now practice this, again repeating first a left-hand throw and then first a right-hand throw, and then a little back and forth, and try to keep that consistency where each just gets to about eye level in a nice little arc. This teaches the real "trick" of juggling: knowing when to throw. This should also take somewhere between 5 minutes and an hour to get comfortable with.

Fourth, sit now with two balls in one hand and one in the other. Throw with the hand that has 2 first, and just do what you did above, but this time, at the point the second ball thrown is in the air at peak, instead of waiting and just catching both, throw the third ball. You can still just catch them all from here. Practice each direction, another 5 minutes to an hour here, but you might slip into the next step naturally.

Fifth, and finally: rather than just catching at the end there, try to just continue the pattern. You have all of the skills required at this point and you will be "juggling" each time. Once you've thrown all 3 starting from each direction, it likely won't be hard to do a 4th or a 5th throw, which feels amazing to get to, and then it's just smoothing things out and finding consistency.

At that point, try to hit 10 throws, then 30, 100, etc. Getting a string of 30+ might take a day or two to actually get, but it'll likely be addictive and you'll want to just keep trying, and it's easy to do most of these steps while you do other low-hands-use things like watching TV, having a conversation, or listening to a podcast.

This comment may get lost, but maybe it'll also help someone! Juggling is a wonderful little skill to have, and it sticks around for life. I learned a little over a decade ago while in school and actively played with it for about a year, but can still easily resume it today.