Can I obtain a copy of the family register certificate and the family register tag at the convenience store delivery service?

You can get it.
You need to apply for registration in advance. After applying for registration, it will take up to 5 open agency days until the examination is completed.
※If you apply for registration once at the first time, you will be able to receive it immediately at a convenience store after the examination is completed. However, if you change permanent domicile outside the ward, you will need to reapply.