Rather than trying to ascertain what aspects of the Knight's character Chaucer admires from studying the Knight's story, you should refer to the General Prologue to the Canterbury Tales. Chaucer makes it quite clear what he admires about this man. I don't know whether you are studying the work in the original or in modern English. I am quoting only the first eight lines about the Knight from the General Prologue in modern English to give you examples of what Chaucer admired. He describes the Knight first in the General Prologue and presents the Knight's Tale first because this man has the highest social status among the pilgrims. You can see from the very first line that Chaucer thinks very highly of the Knight, whom he calls "a fine and worthy man."
There was a knight, a fine and worthy man
Who from the time at which he first began
To ride abroad had loved all chivalry,
Truth and honour, freedom and courtesy.
Most worthily he fought in his lord's wars,
Had ridden more than any in that cause.
By men of Christian or of heathen birth,
Was always widely honoured for his worth.
After you have discussed Chaucer's description of the Knight, based on and quoting from the General Prologue, you can discuss the Knight's Tale as a separate subject. The Knight's Tale is not intended to reveal a great deal about the Knight himself, but it is intended to be an example of the kind of tale that would appeal to an idealistic man like this Knight. Mainly it deals with courtly love and with knightly honor and courage. It is romantic and idealistic. It has been a while since I read "The Knight's Tale," but I think you can find plenty of examples of courtly love and knightly courage and honor. And you should extract a few direct quotes as illustrations of these virtues.
"The Miller's Tale" follows directly after the Knight's Tale, and you might want to explain that the bawdy tale told by the Miller is intended to be a satire of the romantic tale told by the Knight. In both tales there are two men fighting over a woman--but what a difference!