You can make mased layers to the 2d sprite and cast shaows on it from 2d lighting you also need a diffuse material on them and then use the normal lighting in unity lik "point Light"
1.Could you export package of a sample scene for me to imitate?
2.I should use 3D light or 2D light in 3D scene?
3.How to set Scriptable Render Pipeline and shader graph?