Yes darling, you may layer one gel polish on top of another. Because the removal procedure will harm both layers, be sure you want to paint over the original gel because you won't get it back.
Over a gel base coat, conventional nail paint may be applied. The gel base coat is merely a protective coating meant to prevent gel paint from staining the nails.
After applying gel polish over acrylics and curing it correctly, you may add nail paint or do whatever else you typically do with gel nails. Make sure you're using a nail polish that's safe to apply over gel nails.