Hi @brandonsomai1.2jy65i , welcome to Thunkable! 
Be sure to check out our posts about How to ask Great Questions v2.0 and our Community Guidelines as you get started.
You will need to connect your app to a new data source if you want to change which data source is being viewed in your Data Viewer List. Once you add the Data Source to your project, you will be able to select it from the Data Source in the Data Viewer List properties panel.