I'd recommend starting with understanding the basics of Infrastructure as a Service (IaaS) providers like AWS, Google Cloud, and Microsoft Azure. Familiarize yourself with their core services: EC2 (AWS), Compute Engine (GCP), and Virtual Machines (Azure) for compute power; S3 (AWS), Cloud Storage (GCP), and Blob Storage (Azure) for storage.

Learn about containerization using Docker and orchestration with Kubernetes. Master cloud networking with VPC (AWS), VPC Network (GCP), and Virtual Networks (Azure). Lastly, understand cloud security fundamentals and how to manage costs using tools like CloudWatch (AWS), Stackdriver (GCP), and Azure Cost Management.