It would be helpful if you decide beforehand whether you like granite “with movement” or the granite that is a more static pattern or even a solid color like Absolute Black.
It’s a matter of personal taste, but it is likely you will be overwhelmed with the selection at the granite yard, and if you could narrow it down a bit even before you get started, it will help you.
Also keep in mind that some granite yards talk about “Grade A” , “Grade B”, etc. granite. Typically they are not discussing the quality of the granite, but the rarity. The more rare, the more expensive. The yard may have dozens of slabs of one granite, and only two of another, and that will affect the price. But the rarity has nothing to do with the quality of the granite, or whether it will or will not stain or etch, etc.
Also, be prepared to take samples home, for two reasons. One, is that the granite will look different in your house than at the granite yard, so you need to see the ones you like at your house in order to choose one. Another reason is that it is often helpful to have a sample to “experiment” with. I.e., spill wine on it, or oil, and see what happens. Although keep in mind that the granite will behave differently once it is sealed, it is still helpful to see what happens when you spill stuff on it.