When you submit a quote for one of the available Opportunities, you will find the Opportunity in the 'Quotes' section.
If you reach an agreement with the Customer, open the Opportunity in the Quotes section, go to the details, and click on the button 'I made a deal with the customer'.
At this point, the Opportunity will move to the Deals section and will remain available until the Customer leaves a review for the completed work.
Once you receive the review, the Opportunity will be automatically archived and you will find it in the details of your Balance.