upfront theme issue- slider not working.

After checking with google page speed, I found various issues that recommended

Remove render-blocking JavaScript:

URL… -includes/js/jquery/jquery.js?ver=1.11.3
URL… s/jquery/jquery-migrate.min.js?ver=1.2.1
URL/… js/upcoming_calendar_widget.js?ver=1.8.2
URL/… e-by-email/assets/js/widget.js?ver=4.4.2

Optimize CSS Delivery of the following:

URL/… emes/upfront/styles/global.css?ver=1.0.2
URL/… x.php?action=upfront_load_grid&ver=1.0.2
URL/… n/css/unewnavigation-style.css?ver=4.4.2
URL… s/upcoming_calendar_widget.css?ver=4.4.2
URL… ssets/css/widget/widget.css?ver=20130522
URL/… -home&layout%5Btype%5D=archive&ver=1.0.2
URL/? sccss=1&ver=4.4.2
URL… l/assets//css/shortcode.css?ver=20140212
URL / …gular,700|Roboto:100,300|Milonga:regular

So, I installed Autoptimizer and refeshed the page to found that the slider does not work properly. Blank or /and dark black slides have been added in between real slides. Even after loading upfront, it does not allow to delete the slides.

Also it is requested to guide me as to how could I increase the page speed of my webpages.

Backend access has been activated to enable you to do the needful please.