www.wysiwygwebbuilder.com

Is it possible to enlarge the photo of a slide show

Do you mean a lightbox?
https://www.wysiwygwebbuilder.com/lightboxes.html

Also, note that there are many third party slideshows available:
https://www.wysiwygwebbuilder.com/extensions.html

On the site, in a slide show can we enlarge a scrolling picture?

It's not clear what you mean by 'enlarge'. Enlarge on hover? Enlarge on transition to another image? Need more info.

I'm sorry my english is not so good.
In a slide show when scrolling a photo, is it possible to enlarge it in another window?

Did you check out the extensions?
For example: https://www.wysiwygwebbuilder.com/unitegallery.html