Welcome to Android Central! What make and model of device do you have?
So you're saying that when you open the App Drawer (i.e., tap on the icon that looks like a grid of dots, often with a circle around it), Settings isn't there? You can usually also find the Settings button in the Quick Settings menu. If you have a phone, swipe down from the top of the screen with two fingers. If you have a tablet, swipe down from the top right half of the screen with one finger.