Set variable [$ClientID ; Orders::ClientID]
Enter Find Mode 
Set Field [Orders::ClientID ; $ClientID]
How would I then direct the script to display the last (most recent) record as opposed to the first?
It depends on what identifies the record as "most recent". If this is the last record when the found set is not sorted, add this step:
Go to Record/Request/Page [Last]
If it's not the last record when the records are unsorted, you'll need to use a sort records step and then use go to record to go to either the first or last record--depending on the sort order you specify.