The S3 bucket namespace is global

This means that if you get a name conflict when creating a bucket, it is likely because somebody else in the AWS universe has beaten you to it.

Devise a naming schema that offers some uniqueness; perhaps, use your organization's name or a random prefix/suffix to the bucket name.

S3 bucket deletion tends to propagate slowly. Pay attention to the region in which you are creating your bucket. If you get it wrong, you will need to delete then wait for 20-30 minutes in my experience before you can recreate it in the right place.