How do I change an unlit shader to lit?

So I recently downloaded the farm animals set from the asset store (https://assetstore.unity.com/packages/3d/farm-animals-set-97945#description) and it looks good, but the sheep is not receiving light or making shadows. I know this is because of the reason that the shader it is using is unlit, but I'm not experienced enough to change the shader to lit.

Code (CSharp):

1. Shader "VertexColorFarmAnimals/VertexColorUnlit" {
2. Properties {
3.     _MainTex ("Texture", 2D) = "white" {}
4. }
5. Category {
6.     Tags { "Queue"="Geometry" }
7.     Lighting Off
8.     BindChannels {
9.         Bind "Color", color
10.         Bind "Vertex", vertex
11.  
12.     }
13.     SubShader {
14.         Pass {
15.             SetTexture [_MainTex] {
16.                 combine primary
17.             }
18.         }
19.     }
20. }
21. }

It isn't that big of a code really, so if anyone could help I would be thankful. I read that it would only actually work if the object with the shader (the sheep) already has a texture assigned, but I don't know if that is the same as what has happened here.