Best policy for traffic across leased fiber?

We are setting up our first branch office. There is going to be some consulting help on this, but I do not want to leave everything in the hands of them.

- We are using a local meraki switch to a remote meraki switch over leased fiber. There will not be a firewall in the process. What is the best way to keep only the traffic that matters from crossing?

-Should I block all workstation on the local vlan from the remote vlan?

-Should only block broadcast traffic?

-I need some active directory traffic between servers, but I want to the branch to use its local resources not the main office.