Pulling Data automatically, and keeping it Dynamic

I wouldn't use a google script at all. I would just use the google sheets function

importdata(url)

You mentioned that you needed a subset of the data, so hide the sheet above and then create a reference in another sheet for the fields that you need. Easy peasy -- then just make sure that your sheet is set to recalculate on the interval that you need.

Edit:

Pulling data on an interval:

I believe if you go to 'File' --> spreadsheet settings --> Calculation and then select the Recalculation interval to on change and every hour (or minute), it will automatically pull the data again on that interval.

If you want to have more control over when the data refreshes though you in the above step, set the calculation to `on change' only and then add the following script:

function refreshdata() {
SpreadsheetApp.getActive().getSheetByName('[sheetname goes here]').getRange('A1').setValue('=importdata("[your url here]")')
}

and then add a trigger for the function refreshdata to run on the interval you want the data to be refreshed on.