Glad you enjoyed the book; I too, think it’s a great introduction to motorcycling and a handy reference for the early days of your motorcycling “career”.
Scooters are fine as far as they go, but realize that unless you have a 250 c.c. or higher scooter, you’ll be limited as to where you can go with it (no freeway riding). I would advise against the 50 c.c. class scooters as they just dont have enough power (max. ~30 mph); go for at least a 125 c.c. instead.
Yes, you’re right, scooters have their own sub-culture which is distinct and separate from the motorcycling sub-culture.
Bear in mind though that “scooting” can be just as dangerous, so be sure to wear appropriate protective clothing if you do go the scooter route.