I think the learning curve for finger drumming depends on where you are coming from in terms of a rhythm and music perspective. For me personally, I got my first drum machine (MPC) just about a year ago, but being an acoustic drummer for the past 25 years definitely came in handy. I'm no expert, but If I may, here are a couple suggestions that may help you get going:
-Assign your drums to pads that feel very natural from a positioning perspective. (I have been drumming along to jungle mixtapes on my dashboard for years, so I layed out my samples to emulate my car's dash!)
-Try playing simple rhythms first, eventually building up to more complex routines. A great way to get drum rhythms down is to get familiar with the Standard Drum Rudiments. Even for someone like me who can't really read music, learning the rudiments significantly enhances technique and allows easy translation from what you hear and what your hands are doing.
-Have fun with it
p.s. This forum is a great resource for learning about such things. You are in the right place!