I passed on the GCP ACE exame this week after two months of study and practice. Even though I have experience with GKE and GCS, the exame is widely and it requires you other products besides the flagship ones.
the course and the labs were fundamental, but I strongly recommend you to go beyond and use your free trial credits to explore the products present in the exam’s blue print.
Also, I read most of the documentation posted in this thread.
I only felt confident to book the exame after scoring 85% on the simulator. However, the actual exame questions were a little bit harder for me because it didn’t focus much in Kubernetes, which I have experience. Most of questions focused in GAE, GCE, Storage, IAM, Logging and Monitoring.
GCE: auto scaling principals and health checks are required.
The exame had plenty of questions about GAE: change region, deploy from dev to prod, and app’s versions.
Also, it had questions about CIDR and subnet, so I recommend to study: how to calculate the number of host addresses given a CIDR block.
And last but not least, make sure you know Google-recommended practices for IAM (ssh key, service accounts, groups, least privilege, etc).