Adobe Animate CC HTML5 Canvas As3 loadMovie(); equivalent

I’m an old sudden-newbie attempting to make the transition from Flash to Adobe Animate CC and learning about exporting my banner animations to HTML5 Canvas but it seems like the “industry” is in flux and Animate CC now caters to both Flash Users and HTML5 so I’m finding a lot of conflicting tutorials and advice. This makes my transitioning needlessly confusing. The fact that I am relearning all the HTML I forgot doesn’t help

So I have a couple of general questions that I hope this group can help answer.

In the days of old, When I made a rich media banner in flash, I’d have the initial swf that loaded the max file size for the banner (40k) and then upon interaction, load and unload external swfs or add elements from the library. How is this done though HTML5 canvas now?

This was the closest information I could find online:

And still can’t get it to work. So far I have just resorted to the age old practice of sending the playhead to a label after a button click:

this.btn_1.addEventListener("click", fl_ClickToGoToAndPlayFromFrame_4.bind(this));

function fl_ClickToGoToAndPlayFromFrame_4()

Is there a more “dynamic” way to basically create a polite load banner? Loading images as needed into a “empty movie clip”

Also, optimizing the images confuses me now since they are exported into a sprite sheet. How is the initial load calculated? So does the entire image folder count towards the banner size?

Sorry to appear so ignorant but…well there you go.

I really appreciate anyone taking time to answer.