Wonderful! The net displacement of the ball is $$0$$ because it returns to its initial position. As velocity is displacement divided by time taken, the velocity will be $$0$$.
The numerical value of position increases as you go to the right, or as you go up; it decreases as you go to the left, or you go down.

Because we are considering motion in one-dimension (1-D), you can either go up/down, or right/left. 2-D motion is a combination of going horizontally as well as vertically. We don't cover 2-D motion in this Chapter. We will do it in the next Chapter!