Piano Forum

Nearly everybody can walk.  this requires a steady rhythm generated by the brain and sent to the leg muscles. It alternates sides, the way 4/4 time has strong beats and weak beats alternating.  funny thing, the majority of music is in 4/4 or 2/4 time.  
nearly everybody can run.  This involves similar rhythm, but faster.
The trick is connecting that existing brain circuit, to the hands and fingers.
Many young students get too involved in emotion, in varying the rhythm according to some feel for emotion, drama, climax and relax.  This should come years after the sense of rhythm is established. NOT in the beginning.  I practice my new pieces steadily until the movements and notes are learned,  Starting very slowly so I make no mistakes, then faster and faster.   Then I add emotional tricks as I feel necessary.  (Possibly not enough for some listeners)  
I prescribe a regime of marches, and if you can't find those, hymns.  Onward Christian Soldiers is in every protestant hymnal available at charity resale shops for not much.  Pretend you are marching.  Move your feet in simulated steps if necessary.  Until your hands get the hang of it.  
A metronome is a crutch, and should be used very sparingly, only in the beginning. 60-80 bpm should be the desired speed in the beginning, unless you need to go slower for note accuracy.  
If you get beyond simple rnythm, try J P Sousa marches as published in Everybody Favorites Piano solos for the Young Student, or similar fifties compliations.
If that is too hard, start by playing recordings of marches in your back yard.  March around in rhythm.  This would reinforce your sense of the walking circuit.  Everybody has one, walking upright bipedally is wired into the normal human brain,  Salamanders would have no clue, one foot at a time is their gait,  but we do.   
Best of luck.