Hi,
There are a number of reasons why your site can be slow. For example, it can be because of:
hosting provider
size of site on hosting providers
too many plugins
not enough memory
Just because you have installed WP Cache doesn’t mean you’ll have a fast site right away. You have to make some changes to your files maybe even compressed them i.e javascript and .css.
Try to use another tool to see what they recommend. Here is another website which will provide you with what can be done.
https://www.webhostinghero.com
