You might drop in some text at frame one, and then add in the rest of your message word by word and frame by frame. You hit play to see the sequence, and then when all is well, export the result as a Shockwave movie. Going further you can add further timeline 'layers' where you might add a sound effect, such as a 'click' that plays as each word appears or add a coloured background that changes as the sequence plays. Adding motion such as showing text or a football flying in from the side is straightforward too. Here you place the object, it could be a piece of clip art, at frame one and place another copy say at frame 30, and make each of these into key frames.
Key frames determine the start and end of a movement.
Next you get Flash to do some 'tweening' and it will then generate all the stills in between. There are numerous ways to tweak the tweening to achieve the result you need. For example, the text can grow, twist, fade or change colour as the sequence runs, while the bouncing ball can spin, distort or morph into some other object as it moves across the screen. You can also define a custom movement such as making a ball bounce. As a person that confesses to a lack of skill in this area, this was the point at which I fainted.