For some reason I haven’t managed to fathom yet, you can only see a “Leave a comment” box on the page showing a specific post.
On the first page you see, the blog contents are there, but no comment option or links to social media. Duh!
So if you want to comment, you can either find the blog post from the links in the right hand column, or (weirdly) by clicking on the date at the top of the relevant post. Not the title – that would be too obvious! The page which appears looks disarmingly similar, but there is now a comment box at the bottom.
One day I’ll figure out how to modify WordPress themes (or just find a better one) and all will be as it should be – but for now, it’s up to you, and I can only apologise.