Steeping is just giving your
juice a chance to age & blend properly. Most places you order from will mix your
juice after you order it so it will be very fresh when it arrives. Some are fine to vape right away while others might need time to mature.
You'll also see that many people steep differently...warm baths, shaking several times a day, leaving
juice in a dark cabinet with the tops off etc...you'll find what works best for you once you find the juices you like. But make sure you don't throw away a juice because you hate it the first time you try it. Depending on the juice it may take a couple of days or weeks but odds are that it'll taste totally different after you've given it a little time.