How do I play music located in my Icloud Drive on my Iphone without joining Apple music?

I don't think this is possible with any standard app. I think there may be special ones you can find on the web which work outside Apple's music library but it doesn't seem to be a common thing. I think if it were than easy, and free, nobody would sign up for Match or Apple Music. 🙂

iCloud Drive is not a streaming service.

While you can store music files in iCloud Drive, it is just that. Storage.

You need an iCloud Music Library to get streaming. That comes with a paid subscription to either iTunes Match ($25 per year) or Apple Music ($10 per month or $100 per year)