Only if you have taken snapshot/volumes then only you can get it back. Check the snapshot and volumes in the console and if you don't have then you cannot recover anything. And if you have root volumes, then make a snapshot and from the snapshot make an image then after from the AMI launch a new instance for the image just created.
Do checkout AWS Online training to learn more about AWS.
You can refer to the below video tutorial to know more about EC2 instances.