Hello Tom,
Thanks for submitting a question about page optimization. You will want to pay attention to the recommendations these services provide. They will typically be able to isolate elements of the site that might be taking a while to load. And remember the site will move faster once the various resources are cached both on the server and in the users browser.
So you will want to make sure the site is using some kind of caching on the back end. There are many WordPress plugins that can help with that, and your host may also have some good recommendations for you.
Also, make sure that the images you are loading on the site have been optimized for the web. Large unoptimized images are most often the culprit of a slow load time.
Best,
Christopher M.