Hi Tony, great to see new blocsapp users.
I’d review some of your choices because while your content and chemistry course are probebly perfect, the website itself looks dated.
I’d avoid small pictures, images with blurred edges and fussy frames. If you must have frames, shadows, gimmicks choose one style of presentation and stick to it.
In some places you have text with “more” to reveal more text. Ditch that and put all the text in. It’s just annoying to have to click to reveal.
It’s not my kind of site, but presentation may be secondary to the people who wish to take your course.