It’s great that you’ve decided to learn one of the most demanding certification in the industry. GCC Professional Cloud Architect will definitely add value to your profile.
For learning any Cloud Computing (Google, Azure or AWS), Linux knowledge is not mandatory but knowing the Linux administration is good when you deploy Linux machines on the Cloud.
Windows based VMs also available in Cloud but majority of them are Linux machines.
If you know the basic Linux command lines, you would be able to setup VMs on the Google Cloud from GUI or Command Line Interface.
You’re good to go for the GCC Professional Cloud Architect Certification.