Hi, @Md Safwathullah,
As you mentioned that you are good at cybersecurity, I will try to show you a big picture view of the top 10 security concerns for cloud-based services you should be aware of.
Hijacking of Accounts
As per job role you can opt for a cloud security engineer where the Cloud Security Engineer provides cybersecurity expertise in the analysis, assessment, development, and evaluation of security solutions and architectures to secure applications, operating systems, databases, and networks.
AWS is the best choice for you to start your career as a fresher. All the AWS Certification Training is best to begin your learning. You can upskill you career into the Cloud Computing domain for freshers.