Storage– Like most fried bread products, beignets really are best fresh but will keep in an airtight container at room temperature for 2-3 days. Or you may freeze them for 1-2 months.
Temperature– I highly recommend acandy thermometer. It will help both in getting the temperature where you need it for the water, to activate the yeast, and for the oil. You can pick them up online or find them at your grocery or big box stores. They are inexpensive and extremely helpful.