Welcome to Android Central! You are presumably talking about the App Drawer, which is the list of all apps that you bring up by pressing that icon that looks like a grid of dots. You typically can't arrange that list unless you install a 3rd party launcher like Nova Launcher Prime (the function you're looking for isn't on the free version).
You can always drag and drop any or all of your apps (as shortcuts) to the homescreen and arrange them any way you like. You can also create folders (if you have Jellybean or above) by dragging one shortcut onto another.