Checkout blank page

I keep getting a blank page in my checkout page. I hit add to cart and nothing is added (shows nothing in the cart module either).

<div id="content">


					<div style="display:none;"><a rel="{handler: 'iframe',size: {x: 480, y: 140}}" id="hikashop_notice_box_trigger_link" href="/ms/index.php/checkout/checkout/notice/tmpl-component"></a><a rel="{handler: 'iframe',size: {x: 480, y: 140}}" id="hikashop_notice_wishlist_box_trigger_link" href="/ms/index.php/checkout/checkout/notice/cart_type-wishlist/tmpl-component"></a></div><div class="hikashop_submodules" style="clear:both">
</div>

<!--  HikaShop Component powered by http://www.hikashop.com -->
	<!-- version Business : 2.0.0 [1212121842] --><div class="hikashop_footer" style="text-align:center" align="center"><a href="http://www.hikashop.com" target="_blank" title="HikaShop : Joomla!™ Shopping Cart Extension">HikaShop , Joomla!™ Shopping Cart Extension</a></div>

I logged out and then back in, and it seems fine now. I assume this was because I was changing the settings in the backend. But all I changed was the workflow.

I think that your workflow had only login on the step one, and if the user is already logged in so the first step is a blank page.
What you can do is change the workflow, or edit the view "checkout / step" and check if it's empty then submit the form to go automatically to the next step.

Yeah, I was editing the workflow as I was logged in. Is there an explanation of the workflow steps and what they do? I'm trying to simplify the process as much as possible. But when I take certain things out like "confirm" for example, everything stops working. What are the necessary steps to checking out and what can be taken out? What does each one do?

You can see the integrated documentation, it explains the different steps.
HikaShop > Configuration > checkout, and "Help" in the toolbar.