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

You can get it.
You need to apply for registration in advance. After applying for use registration, it takes up to 5 open agency days to complete the examination.
※If you apply for use registration once for the first time, you will be able to issue 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.