You can look at the words in front and behind it, because they refer to this big word. You may find a synonym of the word or a close reference. So for example in this sentence: I was excited and ambitious to learn about cars today. So this is a easy example. You can use exited to define ambitious if you dont know what ambitious means.
To make a distance-time graph, put time on the horizontal axis and distance on the vertical axis. Time is the independent variable, and distance is the dependent variable because its value changes based on what the time is. For example, this is the graph of a person going for a walk. From 0 min to 10 min they are walking slowly, then from 10 min to 15 min they stop and take a break. From 15 min to 20 min they walk more quickly, then stop again at 20 min. The steeper the slope, the more quickly it is moving, and if the slope is 0 (horizontal line), it is not moving.