Hi there. im having a ton of problems making a workflow that sends an email notification when somebody assigns you to the sales team of an opportunity. The only thing that i achieved is a workflow that sends two emails. the first one seems to be OK but i dont know how to make it send only one mail. Somebody talked me about using a checking condition and when that works, it sends the email. however, i dont know how to use this tool. can somebody please help? If i didnt explain myself good enough please ask.

This has been my template for the workflow:

P.D. The record is create button is selected

This is what somebody sent me for the workflow but its an example done with the opportunity entity.