Static site redesign in wp, SEO, link structure

I’m redesigning an old static site in WP and I don’t want to lost whatever Google love I’ve developed over the years. I’ve already set up my new pages, but they currently don’t have the same link names as the wp site, e.g. for the “services” page, the old site: pet-sitting-services-rates whereas the new site is just services-rates.

I had recently changed the link names to improve my seo. But now, if I change them won’t I lose all my indexing to the old site?

Also, if I were to change the wp links to match the old links wouldn’t that screw up my page set up? I already had the experience of putting up a wp page and then deleting it and then reinstating it. The reinstated page insists on coming up “page-2” instead of just “page”

What’s the best way to handle this? Thanks.

Install Advanced Permalinks and set the URLs of the new pages to match those of the old ones. You don’t have to change any URLs unless you want to. I’ve done the exact migration you’re doing and kept every URL the same – nobody would know the site was running on WordPress after the change.