While reading, david encounters a word he doesnt know. what is the first step he should take to figure out the meaning of the word?

Look at the surrounding context.

For example

Jeremy was so ecstatic that he had made friends, that he began jumping up and down.

To figure out the meaning of ecstatic, you would think about the clues: 'made friends' and 'jumping up and down'. These both lead you to the idea of being very happy or excited. The actual definition is feeling or expressing overwhelming happiness or joyful excitement ...