So I found this image on Google and wanted to try and recreate this graphic and animate it. The part I am talking about is the Purple to Pink gradient waves at the top left of t
Fill the entire container with a rectangle, having a linear gradient at angle. Then you can add your waves and animate them.
If you need to show waves in the smaller inner rectangle either add another one or use clipping with the clipped area dimensions.
Either way, here's a start: