G to Csus2
How to transition from a G chord to a Csus2 chord.
The G → Csus2 transition is the same I → IVsus2 move in the key of G or any key where you're playing G shapes.
Chord shapes
Play the G chord in a G shape and transition to Csus2 in a G shape. Lift your first finger off and move your second finger down a string.
GFull
Csus2No 3rd
Anchor fingers: finger 3 on B string (fret 3), finger 4 on high e string (fret 3)