Shared hosting is generally slow, so you need to tweak settings to get maximum out of it. For example, setting Php >7 will improve loading speed a lot. However, you can't improve much and should set a goal of 2-3 seconds loading time depending on the design.
Unlike static html pages, wordpress sends too many php and database calls for each page load, so the loading speed of wordpress sites is relatively slow. Using a cache plugin like WP-rocket, litespeed etc will reduce these calls. If you have adsense, your loading speed will be up to 5 seconds on a shared hosting. Always remember that loading speed is important and the metrics in Google insights, Pingdom, GTmetrix etc will only hint at scope of improvements. If your site loads within 1 sec and Google shows < 30 score, you can safely ignore it.