If you want to keep your custom titles and descriptions for the products already in your store, you can follow these steps:

1. Make sure to turn off the title and description synchronization feature in the Turn 14 app settings.
2. Migrate the products over to the Turn 14 app.
3. Once the migration is complete, your products will retain their custom titles and descriptions without being overwritten by the Turn 14 app.

By disabling the title and description sync and migrating the products, you can preserve your manually created content for those products.