Need help with outline shader

Hey, everyone, I am very new to shaders and just started learning last week.

Right now I am having troubles with creating an outline shader. This is what I have so far but it isn't working it basically creates a huge black blob around the model lol.

 Shader "Custom/OutlineShader"
 {
     // Variables
     Properties
     {
         _MainTex("Main Texture", 2D) = "white" {}
         _AmbientOcclusion("Ambient Occlusion", 2D) = "white" {}
  
         _OutlineWidth("Outline Width", float) = 2
         _OutlineColor("Outline Color", color) = (1,1,1,1)
  
         _ZValue("Z Value", float) = -0.4
     }
  
     SubShader
         {
                 Tags{ "Queue" = "Transparent" "IgnoreProjector" = "True" "RenderType" = "Transparent"}
             Pass
             {
  
                 ZWrite Off
  
                 Blend SrcAlpha OneMinusSrcAlpha
  
                 CGPROGRAM
                 #pragma vertex vertexFunction
                 #pragma fragment fragmentFunction
  
                 #include "UnityCG.cginc"
  
                 struct appdata {
                     fixed4 vertex : POSITION;
                     fixed3 normal : NORMAL;
                 };
  
                 struct v2f {
                     float4 position : SV_POSITION;
                 };
  
                 float _OutlineWidth;
                 float4 _OutlineColor;
                 half _ZValue;
  
                 v2f vertexFunction(appdata IN)
                 {
                     v2f OUT;
  
                     OUT.position = UnityObjectToClipPos(IN.vertex);
                     float3 normal = mul((float3x3)UNITY_MATRIX_IT_MV, IN.normal);
                     normal.z = _ZValue;
  
                     OUT.position = OUT.position + float4(normalize(normal), 0) * _OutlineWidth / 2;
                     OUT.position = mul(UNITY_MATRIX_P, OUT.position);
                     return OUT;
                 }
  
                 fixed4 fragmentFunction(v2f IN) : COLOR
                 {
                     return _OutlineColor;
                 }
                 ENDCG
             }
  
             Pass
             {
                 CGPROGRAM
                 #pragma vertex vertFunction
                 #pragma fragment frag
  
                 struct appdata {
                     fixed4 vertex : POSITION;
                     fixed2 uv : TEXCOORD0;
                 };
  
                 struct v2f {
                     fixed4 position : SV_POSITION;
                     fixed2 texcoord : TEXCOORD0;
                 };
  
                 sampler2D _MainTex;
                 sampler2D _AmbientOcclusion;
  
                 v2f vertFunction(appdata IN)
                 {
                     v2f OUT;
  
                     OUT.position = UnityObjectToClipPos(IN.vertex);
                     OUT.texcoord = IN.uv;
  
                     return OUT;
                 }
  
                 fixed4 frag(v2f IN) : SV_Target
                 {
                     fixed4 mainTextureColor = tex2D(_MainTex, IN.texcoord);
                    
                     fixed4 endColor = mainTextureColor;
                     return endColor;
                 }
                 ENDCG
             }
            
         }
     }