Eliminate render-blocking JavaScript and CSS in above the fold content

Hello, I have been working on my wordpress site using the Google Page Speed Insights tool:
The results have come back that I need to "Eliminate render-blocking JavaScript and CSS in above the fold content".

As far as I can tell, plugins such as smush, hummingbird etc should help me with most of my other steps, but I have no idea how to even start addressing this issue. Can you please advise of any next steps? Many thanks