It’s easy to get lost in the data functions available on the Samsung Galaxy S4, but a phone is still a phone.
By default, the phone app on the Samsung Galaxy S4 should be at the bottom of the screen - just tap it, and a dial pad should appear. If the phone icon is not there, tap the Apps icon in the bottom right, and swipe left and right until you find Phone in the full app list. In that case, if you want to move the phone app to your home screen, hold your finger on the icon, drag it to whichever screen you want to put it into (or the quick access area at the bottom), then release your finger. After opening the phone app, tap the numbers you need and hit the green phone icon in the middle at the bottom to start the call.
Along the top of the phone app you can also access tabs for recent calls (logs), favorite contacts, and contacts. Through all of these tabs you can quickly initiate new calls to anybody in your address book. After tapping the contact you want to call, just tap the green phone icon next to which of their numbers you want to call.
You can also scroll down in your contacts and designate custom ringtones for whenever they call you. When receiving a call, your screen will show the number. Swipe the green circle from left to right to answer the call, or the red circle from right to left to ignore it. You can also tap the tab at the bottom to send a pre-set text message after rejecting the call.
There are plenty of options to dig into once you hit the menu key and tap Call settings. These include setting up call forwarding and blocking, designating voicemail provider, and setting ringtones.
That's about all there is to making a call on your Samsung Galaxy S4. Any questions?