On skin studio click the tools menu > start menu animation builder (pro). From here you'll have timing settings, margin settings etc... On the left side of the window with display a visual representation of your animated menu. The animation works like frame by frame. The more frames you have the smoother the animation. FPS is how fast your animation is, frames per second. You can set whether the animation loops or just plays once and you have to set the amount of frames your animation has. Sorry if this information is uber noob but just trying to help

Here is a great tutorial on how to animate a start button : https://forums.wincustomize.com/361485

The concept for start menu is the same