getURL response handing

I'm not a programmer by training, and am trying to use getURL to import data from an external site via their published REST API. I have successfully executed the HTTP GET, passing the proper parameters, and have the json file returned which I can put into a record, but only as straight JSON formatted text.

Now I'm unclear on two things - how do I convert the JSON into XML (assuming that is necessary) and then how do I parse or map the XMLvariables to populate fields within the Creator form?

So my workflow is to pull data from external site via the remote application's REST API, and then get that data (variables) into the appropriate fields within Creator.

I've reviewed the documentation and don't know anything about XML - so a dumbed-down explanation of the steps would be greatly appreciated!!