I'm wondering is there is a way to create 2 Amazon SQS queues: 1 for the main activity and the other for backup?
Is there a way to make the first queue send every received message to another SQS queue automatically?
You cannot "backup" an Amazon SQS queue.
However, if you configure the source system to send the message to an Amazon SNS topic, then multiple Amazon SQS queues can subscribe to the Amazon SNS topic.
When doing this, I recommend you use raw message delivery to ensure that the message content remains the same after passing through Amazon SNS.
See: