Hi - here is the wiring configuration expected to connect a Nest:
W1 (usually white wire): - Control Furnace/heat
Y1 (usually yellow wire): - Control AC/Compressor
G (usually green wire) - Control fan for unconditioned air
Rh (usually red wire) - Controls furnace/power
C (usually blue wire) - Provides 24 V constant power to Nest - critical to ensure at least 3.85 V power level for Nest thermostat to control furnace/AC and communicate over wifi.
From your picture, you have all of these wires so keep that pic. as a reference and connect the wires following the expected Nest layout.
J
