You cannot split the form into 2 columns via the layout xml. The term "columns" has a different meaning it Magento. A column acts like a container for the elements inside it and you need all the fields to be in the same container because they should be wrapped in a form.
But what you can do is to edit the template customer/form/register.phtml and change the markup to fit your needs. Copy the file from app/design/frontend/base/default/template/customer/form/register.phtml to your theme app/design/frontend/{package}/{theme}/template/customer/form/register.phtmlkeeping the same path and work your magic in the clone.
Best Answer
Create a custom module
In custom module create a layout file name with
customer_account_create.xml
atapp/code/VendorName/ModuleName/view/frontend/layout/customer_account_create.xml
add below code to this file
Flush cache