Defer parsing of javascript

Hi there - I'm trying to improve my site speed and one thing that keeps coming up is Defering the parsing of JavaScript. I did install a plugin but it created an error on the site. Is there something else that I can try?

Thanks

This is the detail I get from GT Metrix

599.4KiB of JavaScript is parsed during initial page load. Defer parsing JavaScript to reduce blocking of page rendering.

https://www.facebook.com/rsrc.php/v3/yw/r/rI_ANjDtvYE.js (209.4KiB)
https://armafone.com/wp-includes/js/jquery/jquery.js?ver=1.12.4 (87.0KiB)
https://www.facebook.com/rsrc.php/v3/yz/r/YhkywtmtFU0.js (83.6KiB)
https://www.facebook.com/plugins/likebox.php?href=https%3A%2F%2Fwww.facebook.com%2Farmafone&width=150&height=500&hide_cover=0&show_facepile=0&show_posts=0&small_header=1 (55.4KiB of inline JavaScript)
https://armafone.com/ (48.8KiB of inline JavaScript)
https://www.facebook.com/rsrc.php/v3/y-/r/T-D_V7C7Ph6.js (30.1KiB)
https://armafone.com/contactform/js/jquery.validate.min.js (18.2KiB)
https://armafone.com/contactform/js/jquery.form.min.js (12.5KiB)
https://widget.trustpilot.com/trustboxes/53aa8912dec7e10d38f59f36/index.html?locale=en-US&templateId=53aa8912dec7e10d38f59f36&businessunitId=57ab6ac60000ff0005935593&styleHeight=130px&styleWidth=100%25&theme=dark&stars=4%2C5 (11.4KiB of inline JavaScript)
https://widget.trustpilot.com/trustboxes/53aa8807dec7e10d38f59f32/index.html?theme=dark&styleWidth=100%25&styleHeight=150px&businessunitId=57ab6ac60000ff0005935593&templateId=53aa8807dec7e10d38f59f32&locale=en-GB (11.4KiB of inline JavaScript)
https://armafone.com/contactform/js/additional-methods.min.js (11.0KiB)
https://s.trustpilot.com/TPElements/CategoryBadge?index=0&type=badge&businessUnitId=57ab6ac60000ff0005935593&categoryId=4effa3200000640004000120 (8.0KiB of inline JavaScript)
https://armafone.com/wp-includes/js/jquery/jquery-migrate.min.js?ver=1.4.1 (7.7KiB)
https://armafone.com/contactform/js/smart-form5.js (4.9KiB)