Simple shader Parse error: syntax error problem

First time trying to write a cg shader. I am not sure why the following simple shader gives me some error that I don't understand. Any help is appreciated.

 Shader "Sprite/UVShader" {
 Properties {
     _MainTex ("Base Texture)", 2D) = "white" {}
 }

 SubShader {
     Pass{
     CGPROGRAM

         #pragma vertex vert 
         // this specifies the vert function as the vertex shader 
         #pragma fragment frag
         // this specifies the frag function as the fragment shader
         #include "UnityCG.cginc"
             
         // User-specified properties
         uniform sampler2D _MainTex;
         
         uniform float4 _MainTex_ST; // Needed for TRANSFORM_TEX(v.texcoord, _MainTex)
         
          struct VertexInput {
              float4 vertex : POSITION;
             float4 uv : TEXCOORD0;
          };
          struct VertexOutput {
             float4 pos : SV_POSITION;
             float4 uv : TEXCOORD0;
          };
 
          VertexOutput vert(VertexInput input) 
          {
             VertexOutput output;
 
             output.uv = input.uv;
             output.pos = mul(UNITY_MATRIX_MVP, input.vertex);
             // Texture offset - GOOD
             // output.tex = TRANSFORM_TEX(input.texcoord.xy, _MainTex);
             // output.tex = float2(input.texcoord);
             return output;
          }
          float4 frag(VertexOutput input) : COLOR
          { 
             return tex2D(_MainTex, float2(input.uv.xy));
         }
         ENDCG
     } 
     //FallBack "Diffuse"
 }

Also, any idea how I can further modify this to adjust the shader like the renderer.material.mainTextureOffset var? I am trying to make the above code for Sprites since the command mainTextureOffset can't work on Sprites. I am extremely new to this so do ELI5 please!