To calculate Kenji's score at the end of the first level, we need to account for both the points he earned and the points he lost.
Kenji earns 10 points for finding a Silverthorn Dragon and loses 6 points when it scorches him.
So his total score can be calculated as follows:
\[ \text{Total Score} = \text{Points Earned} - \text{Points Lost} \]
\[ \text{Total Score} = 10 - 6 = 4 \]
Therefore, Kenji's score at the end of the first level is 4 points.