How do I turn my already build dreamweaver website in to a responsive website (Mobile friendly)???

There's no ai tool for this? 

Mobile users have very different requirements.  They need quick access to content, lightweight pages that don't overload batteries or data plans, finger-friendly navigation and mobile-friendly forms, etc...  So retrofitting an existing desktop site to perform well on mobile devices usually requires a total site rebuild and careful planning with mobile users in mind.  It's a good deal more than just converting pixels to percentage widths.  Without seeing your current site, I'm guessing you should probably wait on this until you are fully committed to rebuilding a responsive web site.

Hi

We need to see ALL your files to answer your question quickly and accurately without a lot of guessing and questions back-and-forth; simply post a link in the Forum..

If your site is not yet online, and to prevent others from seeing a page with errors, just rename a copy of your home page  (such as "test.html")  and upload it to your server (with any associated files) in whatever folder the original page was located, and simply post a link in the Forum and tell us your problem.

This saves you having to cut and paste miles of code into the Forum for the page and all the dependent CSS, JS etc. files.

I trust this is helpful.

Without seeing your site, it's impossible to say just how much work you're in for, but there is a lot more work involved in designing, building, and producing a responsive site. Converting an existing site usually means rebuilding the structure, laying out and restyling for your break points. Here are a few resources:

9 basic principles of responsive web design

Make It Responsive — Web Fundamentals

Responsive Web Design Basics — Web Fundamentals

16 really useful responsive design tutorials | Tutorial | Creative Bloq

Mobile Web Best Practices | Helping People Make Mobile Web Experiences

If you're really adventurous, you could prototype your RWD project using a different app, and then bring your exported files and assets into Dreamweaver for cleaning up and production: Next-Generation Responsive Web Design Tools: Webflow, Edge Reflow, Macaw - Smashing Magazine

Good luck!