Learn to play the melody of this song with your right hand alone.
Use correct fingering (the numbers between the treble and bass staves) and you will have a smooth melody.
You can add the automatic chords by reading the letters above the treble staff.
The rhythm you add will be a 4/4 rhythm such as a march, pop, rock etc. Begin ver-r-ry slowly with a metronome speed of 60.
When you can play it well at that speed, then try it faster.