Starfield and rendering

I am pretty new to writing renderers and making meshes. So I can safely say that i am not even sure i am in the right direction.
I want to make a starfield and draw it using a custom renderer. I got my star data in a csv and transformed the data to XYZ.
My game object has a mesh filter and renderer. After I convert my data i do the following, without defining any triangles (as i dont see the need for this).

Mesh mesh = new Mesh();
mesh.vertices = vetrices;
mesh.name = "tesst";
GetComponent().mesh = mesh;

In my gameobject i have made a material with no texture atm, i will play with this later if i get to the point i see something. Anyway the material has a billboarding renderer attached which in turn is attached to the mesh renderer. It is a copy paste from a solution on billboarding that from the description is doing what i want.
To Clarify I want to spawn a quad on every vertex that at first I am ok with it being just white, which looks at the camera. My camera will only rotate on the spot, so there is no movement involved in this project.
The renderer is the followin.

Shader "Cg  shader for billboards" {
   Properties {
      _MainTex ("Texture Image", 2D) = "white" {}
      _ScaleX ("Scale X", Float) = 1.0
      _ScaleY ("Scale Y", Float) = 1.0
   }
   SubShader {
      Pass {   
         CGPROGRAM
 
         #pragma vertex vert  
         #pragma fragment frag

         // User-specified uniforms            
         uniform sampler2D _MainTex;        
         uniform float _ScaleX;
         uniform float _ScaleY;

         struct vertexInput {
            float4 vertex : POSITION;
            float4 tex : TEXCOORD0;
         };
         struct vertexOutput {
            float4 pos : SV_POSITION;
            float4 tex : TEXCOORD0;
         };
 
         vertexOutput vert(vertexInput input) 
         {
            vertexOutput output;

            output.pos = mul(UNITY_MATRIX_P, 
              mul(UNITY_MATRIX_MV, float4(0.0, 0.0, 0.0, 1.0))
              + float4(input.vertex.x, input.vertex.y, 0.0, 0.0)
              * float4(_ScaleX, _ScaleY, 1.0, 1.0));
 
            output.tex = input.tex;

            return output;
         }
 
         float4 frag(vertexOutput input) : COLOR
         {
            return tex2D(_MainTex, float2(input.tex.xy));   
         }
 
         ENDCG
      }
   }
}

attached are pictures of the game object before and after running.



Any advice is greatly appreciated!

no matter what i do GetComponent().mesh = mesh; will not be posted correctly