There are probably many threads about this but what are the main differences between the Pennsylvania, Kentucky, Virginia and other styles of rifles? How do you tell on first sight?
Most of the long rifles that are called Kentucky were built in Pennsylvania. The term "Kentucky rifle" became popular following the war of 1812 when a song was written by Samuel Woodworth about Andrew Jacksons win over the British in New Orleans.
In several places in the song reference is made to the Boys from Kentucky and their Kentucky rifles.
Andrew Jackson's backers even used the song to help popularize Jackson in his bid for the Presidency.
Before that and even after that the rifles were more commonly referred to just as "Long Rifles".
As for the "schools" of the Pennsylvania rifles, the gunsmiths often copied the general shape of the stocks in the county they lived in and these shapes were often quite different. The differences are most apparent in the shape of the comb and the underside of the butt.
For instance the Lancaster county stocks often had a rather straight comb, similar to many modern rifle stocks.
The Reading county stocks often had a curved comb, sometimes referred to as a "Roman Nose" shape to it.
The Bedford county rifles were very slender, The "drop" to the comb was large leading some to say they looked like hockey sticks.
The main difference between the "Virginia" longrifles and the Pennsylvania longrifles is the Pennsylvania rifles almost always used brass for their furneture (trigger guard, butt plate, side plate, patchbox cover) while the Virginia rifles often replaced this material with iron.
As was said earlier, there are whole books written about the subject, sometimes available at local libraries. If your area has a good library, you might stop by and see what they have.