Centennial Edition, the 1988 book looks more modern, has short lessons even though there are 52.
Of course with a lot of the old books being online and pdf's that can be downloaded to phones and tablets, the older versions might work for the younger generation who are on their electronic equipment a lot. It can be read on them and the text books can be used on those as well.
There were some speed contests for High School students and they were asked to write only at 100 wpm. I'm sure they cold have or did achieve more as some didn't go to college or a business school. But this shows one of the first for High School Students. HERE is the post and the one below it has some more info.
There was also an older bok on internet archive or Google books that talked about Gregg Shorthand for Jr. High Schools or the younger kids learning shorthand--and this was pre-anniversary or Anniversary. When I find it I'll link it up.
"Gregg Shorthand had achieved the most extraordinary success ever attained by any system in the history of shorthand." John Robert Gregg, 1922
Transcribe (type up) your shorthand notes. You can practice typing up the shorthand from books first, then work on your notes, then your dictation.
Since you probably won't be taking dictation from a business executive and typing up letters, you can use any sound dictation you want to practice writing from speakers.
Use shorthand in school, when you go to college, you will find it very useful.
Finally, Have fun with your shorthand. Draw pictures with the outlines while writing sentences, use shorthand to solve puzzles, create a shorthand book for you study, write a story in shorthand instead of longhand, etc.