I'm working with layers on top of the image of a painting I made. How do I pick colors from the original image using my stylus and have them appear in my brush or my palette or color picker? Thanks for helping

The quickest way is to press and hold the Ctrl key then the Colour Selector Tool will be temporarily activated and the cursor will look like an eyedropper/pipette. Then you can click anywhere on the canvas and the colour there will become the selected colour, as indicated in the main colour selector docker, and your brush will paint in that colour. Release the Ctrl key and you're back to whatever painting tool you were using.
For more detailed control you can select the Colour Selector Tool from the Toolbox (looks like an eyedropper/pipette) or use the 'P' keyboard shortcut. Then, the Tool Options docker will give you various options for its behaviour including adding the selected colour to one of your palettes.

https://docs.krita.org/en/reference_man ... 20selector