As this is a piano tutorial the key of C major may have been better since it is the easiest scale and uses just the white keys, however I feel that the key of F has a little more of a soulful touch for an R&B tutorial. Plus the the key F Major uses also all the white keys except Bb (A#).
I am basically playing the 2-5-1 progression. In every scale the 2nd chord is a minor, 5th is a seventh (or dominant) and the 1st is the major chord.
In this example we have the below.
2 – G Minor 7th
5- C7 (or dom)
1- F Major
My right hand is simply voicing / extending the chords using the key of F Major.