You have to revise and reorder your code structure.
Try to defer the blocking CSS and JS. Load everything early that is needed to display the first visible content (=above the fold) and load anything else after this.
In your case you could try to locate jquery, navigation and the form plugin scripts in the
<head> and locate the sliders scripts in the footer. If there are no problems locate jquery and dependent scripts in the footer using wp_enqueue_scripts. Generally load CSS in the
<head> and JS before
This review and this waterfall chart are showing the loading sequences of your site. Take a look in the details on how to solve the several issues.
Additionally you should:
- Declare a doctype in the document head
- Use a caching Plugin such as Autoptimize or W3TC
I guess your problems result from wrong load order.
You can use these tools to analyze your site:
They do basically the same with little differences in reviews.