privClaimID variable will be null because the expression assigned to it returns null so the
ClaimData = ... query returns no rows, hence the error.
This Building a Controller Extension documentation may help you with the design of your controller. And in tests, objects such as your
testClaim have to be inserted into the database to have an
Id value defined.
Note when writing a controller extension, the better way to get the Id value is:
privClaimID = controller.getId();
Your SOQL query does not return any rows while you are trying to assign it to actual sObject. You should set testClaim.Id in yout test class to Page parameters, so in your controller you can get privClaimID from page params.
I also strongly recommend you to post your questions with actual code and not screenshots, it makes answering your question a lot harder.
PageReference myVfPage = Page.YourVFPAge; Test.setCurrentPage(myVfPage); ApexPages.currentPage().getParameters().put('id', testClaim.Id);