Here are some general tips for speeding up your site:

1. Please note that a significant role in site speed is held by the server itself, so you should make sure that you are using a reliable hosting provider with fast and secure servers.

Click here for a list of hosing providers recommended by Envato.

2. You can analyze your site speed on GTMetrix.

3. Optimize your images with a tool like JPEGmini. 

4. Install a plugin for cache, such as WP Fastest Cache, W3 Total Cache or or WP Rocket. 

5. Enable gzip compression on your server. Paste the following code to the .htaccess file located in your theme’s root directory:

<ifModule mod_gzip.c>
mod_gzip_on Yes
mod_gzip_dechunk Yes
mod_gzip_item_include file .(html?|txt|css|js|php|pl)$
mod_gzip_item_include handler ^cgi-script$
mod_gzip_item_include mime ^text/.*
mod_gzip_item_include mime ^application/x-javascript.*
mod_gzip_item_exclude mime ^image/.*
mod_gzip_item_exclude rspheader ^Content-Encoding:.*gzip.*
</ifModule>

You can read more about gzip compression here.

6. Leverage browser caching. Please see this article. 

7. Use a PHP version of at least 5.6 in order to process PHP code faster and to fix older version bugs. WordPress now recommends using a PHP version of 7.0 or greater.