There are several possible reasons could be running slowly. In most cases, it's because your hosting server is running slowly.
Here are a few ways to investigate a slow site load:
1. Make sure you have no excessively large images.
2. Check to ensure you do not have too many fonts being loaded.
If you are using a service such as Google Fonts or Adobe Fonts, make sure you have ONLY selected font weights and fonts that you intend on using to be loaded. The browser has to load each font on the page even if you are not using them, so having too many being loaded can drastically increase site load times.
3. Check to ensure you do not have a plugin that is causing a slowdown.
A good way to test this is to temporarily disable all of your plugins. Having too many active plugins can increase page load times as well, so it's a good idea to only keep the ones you need active.
4. Run a page performance test on your site.
If you score high, then your host is most likely running slowly since your page resources are loading quickly. If this is the case for you, send a screenshot of your results to your hosting provider and ask if they can help.
Here is a speed test site you can use: https://gtmetrix.com