Database app approach

I am digging in this forum but could not realize which way to start.
I need to build an app in Swift that searches in its internal database for a ZIP CODE and retrieves the street name, just two columns ZIP and Street but it is a list of more than 20K ZIP codes lines.
The user will be able only to search not edit, add nor delete.
I learned and please correct me if I am wrong:
CoreData is good for small databases, and can not import from a list of ZIP codes I already have, neither allows to open the coredata database to edit/copy or add outside of the app, so How Apple wants us to use CoreData if the users must populate the database in the iphone.
SQLite in Swift is fast but there is not many good tutorials in the internet, most of them show only how to work with CoreData.
I just found one or two tutorial in Swift SQLite. No one shows how to import data from other database, To work with SQLite in Swift I will need a wraper like FMDB or SwiftData, the documentation is too technical for my knowledge so I have no idea which one should I go.
Hope somebody can help me and show me the direction and maybe some help in this journey as well.
Jade.