Drawing a cone and cylinder I am stuck

Hi,

I need to draw a cone and cylinder but I have written some code but doesn’t display anything:

using OpenTK;
using OpenTK.Graphics.OpenGL;
using System;
using System.Collections.Generic;
using RS.Common;

namespace GraficaDemo
{
    public class Con : BaseObject
    {
        public Con(Vector3 position, int iShaderProgram, PrimitiveType drawType) : base(iShaderProgram, drawType)
        {
            var data = new List<float>();
            var indices = new List<uint>();
            var h = 100;
            var r = 50;
            double theta = Math.PI / 4;
            int M = 50;
            

            double x;
            double y;
            double z;

            for (double i = 0; i <= h; i = i + 0.1) {
                for (int j = 0; j < M; j++) { 

                x = (h - i) / r * Math.Cos(theta);
                y = (h - i) / r * Math.Sin(theta);
                z = i;


                data.Add(DataConverter.ToFloat(x));
                data.Add(DataConverter.ToFloat(y));
                data.Add(DataConverter.ToFloat(z));

                }
            }
            

           
            model = Matrix4.CreateTranslation(position);

            Load(data.ToArray(), indices.ToArray(), true);
        }
    }
}

The Load() function is wrote by my teacher but he doesn’t want to explain how can I make the VBO or indices so I need those too but I don’t know how to make them or generate them…and I can’t even know if the code it’s good.

Thanks a lot !!!