Junior High, High School, Choosing a Level, Samples
The curriculum was designed for K-12 students, but there is going to be some tension between proficiency level and grade level depending on your students, especially for newcomers with zero English in Junior High or High School. I usually recommend choosing a level from the curriculum which has content as close to grade level as possible (see the chart below). There are notes as well as scaffolds in the lessons for helping students at lower proficiency levels.
Chart which correlates grade level and proficiency level with Kid-Inspired levels:

Here are a couple of other resources you might also find helpful: