I have 2 apple ID s. I want to delete one and keep the other. How do I delete this one ID and keep the other?

All purchases made using an Apple ID are tied to the ID. Delete the ID and you will need to download them using your new ID. Make sure you sign out from the places in the 4th link before deleting the ID.

How to delete your Apple ID account

Apple ID – How to Delete

Delete Apple ID (new)

What to do after you change your Apple ID or password - Apple Support     

If you want, you can keep the ID, and just stop using it. Then you can try setting up Family Sharing between the IDs if you want to be able to share purchases made with the IDs.

Family Sharing

Family Sharing - Set up