If you can, test the TDS of your tap water. Usually anything under 200 ppm is ok, as long as its not heavy in iron or anything like that. It is also smart to let it sit out for a day or two like mentioned above, especially if there is chlorine in it, it also helps with managing ph. If you have to use RO or Distilled water because your tap has to high of ppm, you can always dilute your tap water with RO or distilled.
Your going to need a ppm meter(or EC) anyways so you might as well test the tap when you get one, Id suggest getting good quality ph and ppm meters(or EC-what I use) that are waterproof, don't waste your money on the cheap ones, you'll just end up getting a better one later.