If it's 2D animation you're doing, you could choose a character to work with and start off with some walk cycles, turnarounds or lip syncing to funny audio clips. If you're doing stop motion stuff, then you could get together some objects and make them interact with one another; heck, the first animation I ever made through that method was a toy cat running around a brass palm tree!
Also if you need a program for compiling frames, then Monkeyjam does a good job, although it's not very advanced in technical terms; you can make a really nice, smoothly flowing animation at 24 frames per second. Hope that helps!