The standard meaning of an opening bid of 1 No-trump is:
15-17 HCP. We don't add long or short suit points, because No-trump is essentially saying "I have no distribution."
No more than eight cards in your two longest suits. No singletons, no voids, and no more than one doubleton.
Usually, no five-card major. And we'll talk about that one.
Here are five questions about opening No-trump. See how you do. Then you'll get to play a nifty No-trumps hand. Have fun!