Sparks
Let me clarify the secondary chords for you.
First, each scale, whether minor or major will have 2, 3 and 6 but the use of those notes as chords differ (in other words, there are different uses in a minor key than a major key). If you want to play a song in a major key, then you would use the secondary chords (2,3 and 6) as either major or minor chords. Usually they are major.
In the Key of A = B, C# and F# would be the secondary chords and the song would use those chords as either minor or major forms.
Conversely, you would use the minor key should you want to play a song in minor. However, the 2, 3 and 6 are not used in the same way (that is a topic for another day)
Hope this helps.
Dave