Where are the primary and secondary tab blocks?
They are available under other names (I think one is called "Tabs") when you used the the minimal installation profile. 

But you can import the blocks by entering the code of the files

profiles/standard/config/install/block.block.seven_primary_local_tasks.yml
profiles/standard/config/install/block.block.seven_secondary_local_tasks.yml 


into the Single config import located at 

admin/config/development/configuration/single/import


(this requires the config management module to be enabled)