DW settings

There's no magic button for building mobile friendly websites.  In most cases, you must re-build your sites with mobile users needs in mind.  The simplest way is to use a Bootstrap responsive starter template in DW.

1. Define your local site folder.

2. Go to File > New > Starter Templates, pick one and hit the Create button.

3. Save your file as index.html

Learn more about Bootstrap's mobile-first framework below.

• https://www.w3schools.com/bootstrap4/
• https://getbootstrap.com/docs/4.6/getting-started/introduction/

Post back if you have any more questions.

Have a look at 

https://helpx.adobe.com/dreamweaver/tutorials.html?guid=1A508865E9A84DFBAA1BCF90F2D2321F&product=DRWV&product-version=20.2.1.15271&location=CCXStart&location-version=2.7.2.15&trackingid=1NZGDC8F&mv=in-product#

in particular

https://helpx.adobe.com/dreamweaver/how-to/media-queries.html?playlist=/services/playlist.helpx/products:SG_DREAMWEAVER_1_1/learn-path:key-techniques/playlist:topic/set-header:css/en_us.json&ref=helpx.adobe.com

You could also go to the learn section in Dreamweaver

Typically, that kind of issue is caused by a lack of content. There are a lot of ways to fix it, but it's hard to say what would work best without seeing what you already have.

Could you share a link to your work in progress so we can take a look?