[Chartjs]-How to create line graph use chartjs?

1) Here is an example for how to only show the line and not the fill below. Basically, you just use the fill: false option.

var myChart = new Chart(ctx, {
  type: 'line',
  data: {
    labels:
[0.05, 0.1, 0.15, 0.2, 0.25, 0.3, 0.35, 0.4, 0.45, 0.5, 0.55, 0.6, 0.65, 0.7, 0.75, 0.8, 0.85, 0.9, 0.95, 1],
    datasets: [{
      label: 'Dataset 1',
      borderColor: window.chartColors.blue,
      borderWidth: 2,
      fill: false,
      data: [19304,13433,9341,6931,5169, 3885,2927,2159,1853,1502, 1176,911,724,590,491, 400,335,280,239,200]
    }]
  },
  options: {
    responsive: true,
    title: {
      display: true,
      text: 'Chart.js Drsw Line on Chart'
    },
    tooltips: {
      mode: 'index',
      intersect: true
    },
  }
});

2) There is nothing natively built into chart.js to draw lines on the chart, however the same team has created a nice plugin called chartjs-plugin-annotation that you can use to do this. Here is an example of how to configure a line at the point that you wanted (this would go inside your options config.

annotation: {
  annotations: [{
    type: 'line',
    mode: 'horizontal',
    scaleID: 'y-axis-0',
    value: 2225,
    borderColor: 'rgb(75, 192, 192)',
    borderWidth: 4,
    label: {
      enabled: true,
      content: 'Point Label',
      yAdjust: -16,
    }
  }]
}

Here is a codepen example that demonstrates this.