When I was on the cruise ship my family and I went to a workshop to learn how to juggle. The person teaching the workshop was Michael Holly. He learned how to juggle in college when his friend showed him how to do it. He has made a career out of juggling. I will share the steps that he showed us and also give you the link for his website so you can learn how to juggle yourself. I am getting better with 2 balls but still have not mastered 3.
The first step is to not even use any juggling balls. It is just to make a figure 8 (infinity symbol) in the air with your right hand first and then with your left hand. This helps you to help your brain learn about the pattern that the juggling balls make in the air.
The next step is to use one ball and practice throwing it in the air from one hand to the other. You do not need to throw the ball high up in the air because juggling is just small throws in front of you.
The third step is to use 2 juggling balls. Start by throwing the ball in your left hand first followed very shortly after by the right one. Try to get a rhythm going and picture the figure 8 pattern that you first practiced. Even 2 balls can be challenging to catch.
Before you try to juggle 3 balls it is good to practice just throwing them up in the air and letting them land without catching them. This gives you a feel for the pattern. Start with 2 of the balls in your left hand and throw one of them in the air to the right hand. Before you can catch it you have to throw the ball in your right hand to the left. Before you can catch that one you have to throw the ball in your left hand to your right hand. The whole act of juggling moves very quickly.
Here is a picture of Michael Holly and his link is michaelholly.com He suggests practicing on your bed or couch so that the juggling balls don't bounce away too far. He also says that you can practice in your living room when commercial breaks are on. He says that anyone can learn to juggle. When Michael was a kid his mom took him to the doctor because he did not have good coordination but look at what hard work and dedication did for him!