Getting familiar with Drummer and the Library
Open a new project and select Drummer from the New Tracks Dialog window to create a Drummer instrument. While it defaults to the Rock genre, if you hold the mouse down on that field, you will see that there are other choices. For now, let's go with Rock with Open Library checked.
What you now have is a Drummer region, with the Drummer editor open, and in the Library, you will see the genre choices and multiple drummers within each genre with descriptions of the drummers, and in the Sounds section, a bunch of different drum kits:
NOTE
The "hipper than thou" crowd made merciless fun of the descriptions when Drummer first appeared, but they are accurate and helpful.
The default Rock drummer is Kyle, and he plays a kit called SoCal and a preset called Half-pipe. Notice that with this choice, Drummer changes the project tempo from 120 bpm to 110...