H1,H2 headings use in my knowledge base

Hi there,

I am quite new with the SEO topic and would have some questions regarding the correct use of H1,H2,... headings. On my website will be a knowledge base with information about natural healing methods.

I will have an entry page, screenshot 1, https:// ibb.co/7bRVLt1, which shows the main 9 treatments in the middle as an overview, and on the lefts side is the menu with all different treatments on my website. I will have around 40 treatments.

Lets`s get to the tricky part. For the entry page, I probably should use H1 and H2 headings for the menu side bar, because this gives the crawler the overview of all different treatments of my website, not just the 9 most common.

But when one of the treatments will be opened, the focus of the crawler and therefore the headings, should switch to the treatment itself and not the overview, see screenshot 2, https:// ibb.co/C89LdtZ. So the H1 should be the name of the treatment, and H2 and H3 headings will be used within the text. What would be the best way to use headings for the sidebar in this case? Would you use H4 and H5 headings as I created it in my draft?

Second question is about the footer, what would be the best way to use headings for the footer? Is it even necessary? Complicated could be, that headings will be used differently on each page, so the headings within the footer, will be different on each page. Does it make sense to use it at all for the footer?

--> The pictures/screenshots do not show correctly for some reason, so I had to use the links, with a blank in the middle.

Many thanks for your help :)

Best, Manuel