Hi @B8
You may use "Get item" action that accepts an ID and will fetch only a single item from SharePoint. You may pass ID of the record from the power apps as input parameter:

Or
If you use "Get items" then it would give an array of records. You can use filter query based on your need and only interested in processing single item. In that case, we can write an expression using first() function to get the first element from the array to avoid looping (Apply to each action):

Now, using expression get the created by email address of the first element:

Expression used in the above screenshot:
first(outputs('Get_items')?['body/value'])?['Author/Email']
Similarly, you can use last() function to retrieve the last record from an array.
In the above example, I have taken a basic filter query, but you can write more complex queries as per your need. You may use combination of different actions and expressions to process the record(s) as per the requirement.
If this helps & solves your problem, please remember to give a 👍 and accept my solution as it will help others in the future.
Thanks