You can run it on the free node, i you want to publish it externaly. For more information, check the documentation or the academy courses. For licence node, I think you need to contact the mendix sales department.
It depends on where you want to run your app. Do you want to run it in the Mendix cloud? At the top of the modeler, you can change the button 'Run locally' to 'Run', and click that. That deploys the app to the Mendix cloud.