What's the best way to migrate a database to a server of a lower SQL version? I have Database A on SQL Server 1 that is SQL Server version 2016.
I need to migrate it to Server 2 that is SQL Server version 2012.
Database A is pretty small, only about 5 GB total.

I don't think there's a way to migrate it via a Full backup, so what would be the best way to move the database?...BCP?...or is there better methods?
BCP by itself may not be sufficient as it won't address non-table objects like stored procedures. To migrate the schema, one option would be to use a Visual Studio database project importing it from the 2016 instance and deploying it to your 2012 instance. Afterwards, two options to import your data rows are BCP and the Import/Export wizard in SSMS.