Tap the Contacts icon. Then look for the contact you want and tap that one. Then tap the phone icon (it's a little one) next to the number you want to call (if you have more than one number for that person - like home and work). If you have no contacts and want to add one, tap the + and you'll get a screen to add it to. (Make sure you add it as a Google contact - for your Google address.) The keyboard will come up when you tap in a box that requires information - name, phone number, etc.
(It's not the age - at best, you have 2 years on me. It's just lack of familiarity. I did this stuff for a living.)