I have a 15 amp circuit serving only a single outlet on my deck. It is protected by a GFCI circuit breaker in the home's single 125 amp service panel. I wish to replace the GFCI breaker with a regular 15 amp GE breaker. I will then protect the circuit with a GFCI outlet.
I am familiar with replacing regular breakers with regular breakers, but when I looked I saw that the GFCI has a white wire and a black wire attached to it, while of course the regular breakers have only a black wire. My question is, when I replace the GFCI breaker
With the regular breaker, where does the white wire go then?

The white wire from the cable will get disconnected from the GFI breaker and connect to the neutral bar, with all the other white neutrals.