Hi Shilpi,
Please see the following documentation for this exact task:
Migrate machines as physical servers to Azure
https://video2.skills-academy.com/en-us/azure/migrate/tutorial-migrate-physical-virtual-machines
Realistically, the simplest way is completely dependent on what applications are running on your server. If you just have one application on your server, create an Azure VM (Windows Server) and re-install your application on the server. Then backup your application's data and migrate it to the Azure VM (this is completely dependent on what you have running on the server).
If this is helpful please accept answer.