I have subdivided this answer on how to learn AWS into four levels depending on various levels of learning or expertise.
For the level of AWS Cloud practitioner, it takes a minimum of one month to learn you will learn fundamentals of cloud computing, setting up of the AWS account, AWS management console, S3 Services, etc.
For a level of AWS Architect, it takes a minimum of 1.5 months to learn Identity Access Management, EC2, Database on AWS, Route53, Network Address Translation, HA Architecture, etc.
For a level of AWS Developer, it takes a minimum of 2-3 months to learn AWS SDK, Access Management, Integrate AWS applications by using AWS Lambda, AWS API Gateway, Amazon SNS, etc.
For a level of AWS Operations, it takes a minimum of 3-4 months to learn the concepts like management of the AWS instance and permissions, security management, troubleshooting problems, EC2 configuration, etc.
If you are looking for the certification course, you can sign up for this AWS Certification by Intellipaat that offers Instructor-led training, hands-on exercises, and job assistance.
Also, watch this video on AWS: