Serve scaled images: the properly sized image service can save many bytes of data and improve the performance of your web page, especially on low-power devices (for example, mobile devices).

Optimize images: in simple terms, optimizing your image works by eliminating all the unnecessary data that is stored inside the image to reduce the size of the image file depending on where you are using it on your website.

Defer parsing of JavaScript:

In order to load a page, the browser must parse the contents of all script tags, which adds additional time to the page load. By minimizing the amount of JavaScript needed to render the page, and deferring parsing of unneeded JavaScript until it needs to be executed, you can reduce the initial load time of your page.

Combine images using CSS sprites:

Combining images into as few files as possible using CSS sprites reduces the number of round-trips and delays in downloading other resources, reduces request overhead, and can reduce the total number of bytes downloaded by a web page.

Minimize redirects:

Minimizing HTTP redirects from one URL to another cuts out additional RTTs and wait time for users.

1. Try deactivating all plugins and checking to see if this resolves the problem. If it does, activate the plugins one by one until you find the problematic plugin(s).
2. Try to delete unnecessary plug-ins.
3. Try changing themes or using the default one and see if there is a speed increase.
4. If you are loading pretty large images, you can try optimizing those.
5. Optimize your database through phpMyAdmin.