No Migration is necessary, both Mendix Studio and Pro use the same model. When you create an app via the create new app flow on home.mendix.com it’ll enable both Studio & Studio Pro for development. If you have started in Studio Pro it won’t enable Studio by default. But you can turn it on using these steps:
Open up the project in home.mendix.com
Go to General → Settings
You should see an option to enable Studio
Once you have enabled studio in the project settings you need to enable it for Studio Pro. Open the project in studio Pro.