I made a blank drawing template that puts the very basics for a drawing into a single HTML file. This way I can make numerous simple drawings quickly while I practice the basics.
<!DOCTYPE html>
<html lang="en">
<head>
<title>Drawing 00</title>
</head>
<body style="background-color: #222;color: gray;">
<h1>Drawing 00</h1>
<canvas id="canvas" style="background-color: black;border: 2px solid gray;" height="320" width="480"></canvas>
<script>
const canvas = document.getElementById('canvas');
const ctx = canvas.getContext('2d');
// Drawing code goes here
</script>
</body>
</html>
The basic set-up is such that a reference to the canvas node is made. Then a 2D rendering context is made for the canvas reference. From then on, the Canvas API is accessed via the context as a chained function. For example...
ctx.fillStyle = "rgb(200 0 0)"; //set a color for filled objects ctx.fillRect(10, 10, 50, 50); //draw a filled rectangle
Sets the fillStyle attribute for ctx to red.
Then, the fillRect method draws a shaded rectangle with side length
of 50 pixels at pixel coordinate (x, y) = (10, 10) on the canvas.