It sounds like you want to create a registration page on your website where users can sign up and receive a welcoming message. Here’s a general outline of the steps you would need to take:

1. Create a Registration Form: Design a user-friendly registration form where users can input their information, such as name, email address, and password. Depending on your website’s purpose, you can include additional fields as well.

2. Choose a Technology: Decide on the technology you want to use for your registration form. You could build it using HTML and CSS for the front end and a programming language like PHP, Python, or JavaScript for the back-end processing.

3. Backend Development: Implement the logic for processing the user input from the registration form. This involves capturing the data, validating it, and storing it in a database. You should also include security measures to protect user data, like hashing passwords.

4. Send the Welcome Message: After successful registration, trigger an automatic welcome message to be sent to the user’s provided email address. This could be done using a server-side scripting language or a third-party email service like SendGrid or Mailchimp.

5. Frontend Integration: Integrate the back-end functionality with the front-end design. When a user submits the registration form, the back-end code should be executed, and upon successful registration, the user should see a confirmation message or be redirected to a welcome page.

6. Testing: Thoroughly test your registration process to ensure that user data is being captured accurately, and stored securely and that the welcome messages are being sent as intended. Address any bugs or issues that you encounter.

7. Deployment: Once testing is complete, deploy your registration page on your live website server so that users can access it.

Remember that this is a high-level overview, and the actual implementation details will depend on the specific technologies and tools you’re using for your website. If you’re not familiar with web development, you might want to consider working with a developer or using website-building platforms that offer pre-built registration and welcome email functionality.