You can check the Object names . If it's a custom one and it has relation with that given object then the API name must contain __r.
From this, you can easily find out which one is a standard one and which one is custom.
You are on the right way, you just need to move variables related to the record outside the quotes.
$Profile.Name, "System Administrator"
"https://testrackspace.service-now.com/rack_sp?id=sc_cat_item&sys_id=4bb14bc2c84f4e0087fd91e81c4cff48&sysparm_salesrep=" + Federation_ID__c + "&...
You are getting this error because, the app you are using have no permission for Case Transfer and the logic which you are trying to implement have case transfer mechanism.
This problem can be overcome by proving Case Transfer permission.
Profile->App Permissions ->Transfer Case
You can use all zeroes (e.g. keyPrefix + '0'.repeat(12)). It will never match an existing or future ID. Depending on your use case, you can also generally just use '0'.repeat(15), which is what Salesforce uses internally to represent a null ID. Obviously, the 0-key-prefix pattern doesn't match a specific sObject, but might be valid for some use cases. Note ...
You've not provided the full context of what you're doing, but my best "educated guess" is you need to provide more context for the delete operation. You're probably attempting to delete the actual product instead of the product from an order or opportunity line item. Your query in your @AuraEnabled method also needs to have that context as well so it knows ...