sugarQuery

SugarQuery is primarily for queries.

To create

$acase = BeanFactory::newBean("Cases");
$acase->save()

SugarQuery is for querying, in other words, searching.

To create a case from code you would use the API:

https://support.sugarcrm.com/Documentation/Sugar_Developer/Sugar_Developer_Guide_11.0/Integration/Web_Services/REST_API/Endpoints/module_POST/index.html

Or the BeanFactory:
https://support.sugarcrm.com/Documentation/Sugar_Developer/Sugar_Developer_Guide_11.0/Data_Framework/Models/SugarBean/