Magento collection get last item : You can get magento collection last item as below.
For Magento 2 Last Item Read – Magento 2 get Last Item in Collection
Magento collection get last item Syntax
$collection = Mage::getModel('module_name/model_name')
->getCollection()
->setOrder('Id Desc')
->setPageSize('1');
The above filter will select last record from the collection.