A shuffle beat is a triplet based groove, which means you subdivide each count in 3 parts instead of the normal 2 (8th notes) or 4 (16th notes). The way to count this is by first just counting 1, 2, 3, 4 and then turning that into: 1-trip-let-2-trip-let-3-trip-let-four-trip-let.
If you give each word the same exact amount of length you’re counting the underlying grid of a shuffle beat.
I’ve written down the basic shuffle pattern for this lesson below. For information on pad layout, basic techniques, equipment and more you can sign up for one of the free courses on this website, or at least read this article about the basic finger drumming techniques and the pad layout that I use.