There are a few ways to store bikes in the most space-saving ways. Hanging them vertically is a great option, if you have more than two bikes to store. You can find hooks like these in any hardware store.
In terms of tennis rackets and baseball bats, the best way to go would be to hang them on a wall - again so they don't take up floor space and roll away. For various balls, having a large bin to throw them all in so they don’t roll around on shelves would be the way to go. Putting bubbles and chalk in a plastic bin that is containable is ideal, as it can be easily wiped clean. Jump rope can be hung with hooks from any hardware store.