there is lots of code editor available but if you are a beginner and wants to learn HTML you can go with notepad
Step1 :
Open your window notepad and put the following code
index.html
<!DOCTYPE html>
<html>
<head>
<title>HTML Tutorial</title>
</head>
<body>
<h1>This is a Heading</h1>
<p>This is a paragraph.</p>
</body>
</html>
Step 2:
save this file as .html (eg: index.html) .html is very important
Step 3:
Now run our HTML file as we have saved .html just open any browser and drag and drop to that file into the browser you will see the output.