How to optimise the speed of my website?
One of the main reasons the site is slow is that you may have lots of images which are not optimised for web.
To check which images slow down the site. If you go to chrome, and right click and the 'Inspect' you will see a 'Network' tab which helps you monitor the loading time for all elements.
Click on the 'time' column to sort the entries.
Second you can use one of the WordPress cache plugins to deliver cached content:
https://premium.wpmudev.org/blog/top-wordpress-caching-plugins/
Third, compress your images using a plugin such as WP Smush
Fourth, optimize your WordPress installation using a plugin like WP-Optimize.
Fifth, use a CDN (Content Delivery Network) to deliver your content over the web.