Android phones with no keypad handle speed dials differently than other phones. I know I came from a Blackberry and I had to figure this out because I have too many contacts to have to scroll through each time.
To set a speed dial, press & hold your finger on the screen. A menu will open "Add to Home Screen" with a list of options. Tap "Shortcuts". From the shortcut menu scroll down to "Direct Dial". Your contacts will open and then scroll down to the contact you wish to add and tap it. Now on your home screen you will have an icon for that number. To dial it simply tap it and the phone will call it. You can also do the same thing for a "speed dial" of a contact you text with.
You are limited in the number of speed dials to the amount of space available on your screen. I have the numbers I frequently call on one page dedicated to that purpose.