To directly answer your question I would differ you to the Better Minify Plugin: https://wordpress.org/plugins/bwp-minify/
It will easily let you compress your .js files.
And it will allow you to move your .js scripts to the footer to enhance your above-the-fold loading. HOWEVER I want to point out that moving all of your .js scripts to the footer isn't as simple as it sounds because certain theme elements will require certain scripts to load in-order to display properly. I recommend you do this piece by piece, finding out what works and doesn't.
I would also recommend considering Cloudflare - it's a great and free way to speed up your website AFTER you complete these optimizations.
And a properly setup cache system will definitely help you with your load times also.