To create a visit based on an already accepted estimate go to the estimate detail page and click the "Create Event" button:
In the popup please pick the property that you'd like to service:
(If you have not added a property for your customer yet you need to add a Property first. You can do that on the Properties page)
Here's a quick tutorial on that: Adding a Property for a Customer
Once you clicked the "Create Visit" button you should be redirected to the "New Visit" page with most of the fields already populated.
Please make sure to select the date for your visit, etc and click the "Create Visit" button when done.
Your visit should now show up on the Schedule page.