Normally you want to put 1lb or less of any nutrient at a time...

So if you take your highest number (25....25%) of Nitrogen. That would be 8lbs of fertilizer gives you 2lbs of N for your 2000ft. 1lb /1000ft

But package should have recommended Dimmension rate... is the bag a 5000ft bag? If so you would use half on your yard almost. Just set spreader to the minimum that it comes out well and criss cross the yard until it is out - trying to be even.

Still want to stay under 1lb of nitrogen per 1000sq ft most likely (im a cool season grass guy so not sure on the south)