How to measure pageload times for subpages?

For my bachelor thesis I want to measure the pageload time of a subpage.

Scenario:

I'm already on a fully loaded page, let's say a startpage of an online shop. With the HTML-link element I'm able to preload resources, let's say the resources of a product page of a product you see on the startpage.

Now I want an automated test which simulates a click on that product, giving me the pageload metrics under different connections (Edge, 3g fast, 3g slow) with different link-methods (rel="dns-prefetch", rel="preconnect", rel="prefetch" etc.) for that product page.

I just need a hint if there is any framework or tool available.

Thank you!