Bootstrap beginner question

To add to what has been said, Bootstrap 4 Tutorial is an excellent way to learn Bootstrap. Hopefully after one week you will be able to show the person that osgood_​ quoted, on how to condense the rather long line of classes .

Did you define your local site folder?

Did you save and name your newly created Bootstrap starter page?

Your files panel should look something like this where C:\myTestSite is the local site folder.

Which version of Bootstrap are you using?  It's important to clarify this up front because Bootstrap 4 contains new utility classes that don't exist in Bootstrap 3.  And you must not combine 3 with 4.  Go to Site > Manage Sites > Advanced Settings > Bootstrap.  See screenshot.

Path to image is incorrect:

<img src="file:///Macintosh HD/Users/Design1/Desktop/imagecustom01.jpg" alt=""/>

plus when you get that correct you need to add a Bootstrap utility class to make the image responsive:

<img class="img-fluid" src="file:///Macintosh HD/Users/Design1/Desktop/imagecustom01.jpg" alt=""/>

If you are going to use Bootstrap its best to take a week out and learn the most important utility classes otherwise you'll be like a fish, swimming around in a vast ocean, without any fins

It won't be long before you are writing excellent code like below:

<div class="row ml-xl-0 mr-xl-0 pl-xl-0 pr-xl-0 ml-lg-0 mr-lg-0 pl-lg-0 pr-lg-0 ml-md-0 mr-md-0 pl-md-0 pr-md-0 ml-sm-0 mr-sm-0 pl-sm-0 pr-sm-0 ml-0 mr-0 pl-0 pr-0">

Seriously, I've just see this in someones website, this is how terrible it can get in the hands of the unexperienced

I am not a Bootstrap fan, so I won't comment on Bootstrap. But the path to the image in the code you posted indicates a problem with your local site definition in Dreamweaver. I am assuming you are using Dreamweaver or you would be posting on a Bootstrap forum of some sort.

In any event, a style declaration of max-width 100% is all you need to make an image respond to viewport width. There might be a class you need to assign to your image to make that happen, though. You can try this in your own CSS file:

img {max-width: 100%;}

As for Bootstrap, there are a couple of regular posters here that swear by it and I'm sure they'll jump in.