Once you have generated your schema's markup, you can then go and test it.
Test at Structured Data Testing Tool
You can easily test your schema by copying it and paste it in the Structured Data Testing Tool
All good ? Done!
Now, you can start to add this markup to your own websites as shown here
Some schema's have mandatory fields. The Structured Data Testing Tool will highlight these. You can add these fields by using the back button of the navigator you're using. At this moment, this tool has no way of knowing which fields are mandatory. It's trial and error.