Hi Steven,
In this issue, you could compress your used images using this tools https://tinypng.com/
This is because, most of the time oversize images are responsible for late loading.
Also, if you don’t need to change anything in your website CSS & JS files, then you could minified all of the CSS & JS files. It will help to load your website fast.
Otherwise, there is no other solution for the HTML template. Moreover, HTML template will take time to load and it’s normal.
Best Regards,
ThemeLooks Support Team