FAQs for Sites

The short answer is "not right now", but Google is always adding features, and it is likely you will be able to in the future, especially if the photos are in Google Photos.

A nice workaround, though, is to add the photos to a Google Slide presentation, then embed the Slides into your page.

That is up to you, and really depends on what information you want to share. Maybe this would be a good thing to discuss with your grade level or department. Remember, though, that you won't have time to add content every week, so if you are thinking of "poem of the week", consider preparing months/units at a time, and get the pages prepared ahead of time. You can hide them from navigation until you are ready for them to be seen.