Your score is 148 and your percentile is 58.
Percentile is the percent of people you outscored on the test. Since you are in the 58th percentile, you did better than 58% of the college-bound juniors who took the test at the same time you did. This means you did slightly better than average.
I think that's a typo or an error, and you're in the 48th percentile.
You did better than 48% of college bound juniors, who got an average of 58.