Website simple update and description for Metadata

I have a website at www.pegdenpt.co.uk and want to update some of the text and images. It should be simple, but it seems I can't do this myself, as according to AI.
"The WordPress editor (Gutenberg) is completely empty because the pages use a custom page template from your theme. The content is baked into the template file itself, not saved in the normal content area. That’s why you only see the single grey placeholder image (that’s the only thing actually saved in the page).
So apparently I need to rebuild the site by copying over the live pages, so I have complete control within the editior.
There are only a handle of pages as you can see and should take very little time to someone who can do this.
There is NO metadata on the site and therefore we have a real problem being found by local searches, so I also need all pages, titles descriptions etc added for the right keywords and descriptions, including images.
DO NOT call me and please explain how you can simply do this. I need people with an excellent track record I can trust.
Extra considerations for anyone who can help with Google ads tweaking and ensuring the website and ads work completely efficiently together.