Read the following tutorial:

Web forms — Working with user data[MDN]

In the above tutorial here are the required and optional sections to read:

• Your first form required
• How to structure a web form required
• Basic native form controls required
• The HTML5 input types required
• Other form controls required
• Styling web forms optional
• Advanced form styling optional
• UI pseudo-classes optional
• Client-side form validation required
• Sending form data required

Most of the the lab will be oriented around this last tutorial. It is strongly recommended that you try all the examples in it yourself rather than just reading about them.