I am wanting to get information from Netsuite and save it to my web app. I have classes that send information to Netsuite that then gets processed by a suite script but I am not sure how to get Suitescripts to return information. When I look at the Suitescript documentation there doesn't seem to be any examples or mentions of returning data.
You use a SuiteScript of type RESTlet to create custom API endpoints. You can find bunch of examples in that link to use for your API.
As you mentioned, a SuiteScript handles your GET request. That SuiteScript is a RESTLet. You need to modify the same function inside the RESTLet that handles the GET request, to return any data to your external web app. Don't forget to convert your data to a string, using JSON.stringify(), before returning it.
You could set up and use SuiteTalk which is a native API NetSuite that NetSuite offers in SOAP and REST to fetch data from NetSuite. I personally have never used SuiteTalk and prefer creating my own RESTlets that fetch or post data. Here's a nice video that explains how to create a RESTlet.