Hi @Rod_Connors, welcome to the Asana Community Forum! Let’s see if we can solve this together!
As it stands, it’s currently not possible to import tags to your project using the CSV importer. We have an open request here: CSV importer: import tags - #2 by Shawn2.
I believe you are trying to import custom fields to the tasks that already exist in your project, can you please confirm if this is what you are trying to achieve?
In the meantime, you can find more information in this article.
Looking forward to your reply!