In Can't Live With 'Em, Part One, he was one of the senior students at Borden High School giving tour guides for the grade student students from Degrassi Junior High who were going to be taking part-time classes that year.
In A Big Girl Now, he attended the party at Lucy Fernandez's house that was exclusive to only the older students (and/or just the friends of Paul and Clutch) of Borden High; they wouldn't let Lucy's own friends attend also.
In Taking Off, Part One, he might have been the drug dealer who sold Luke Matthews and Shane McKay acid. The very same acid that caused Shane his life altering brain injury. Since Glen was a brief minor character in his first appearance not very much is known about him. So it remains unknown whether or not if he truly was the drug dealer or just a look alike.