Enhance Contact Form Functionality

My site already looks fine, yet it still lacks a simple but vital feature: visitors cannot send inquiries. I need the underlying functionality that takes a completed contact form, validates the data, and reliably delivers it to my email inbox (or another endpoint we agree on)... (Budget: $30 - $250 USD, Jobs: CSS, Email Handling, Frontend Development, HTML, JavaScript, Node.js, PHP, Web Development)