You want ping to be as low as possible. This is because ping records the time it takes for a "message" to reach it's destination and come back. Therefore, the lower the ping the less time it takes. The less time it takes the faster it is, and you want your "messages" to travel as fast as possible.
For upload/download you want this number to be as high as possible. They are typical measured in megabits/second, so if you download more megabits in one second, you can download large files faster.