Multiple vs single Apple ID among laptops and mobiles

What you choose to do depends on whether or not you want to share data and purchases between your computers and phone(s). If you want to share data and purchases, use one Apple ID everywhere. If you want the data and purchases separate, use two or more Apple IDs.

If you want to share data and purchases,  I suggest you pick the ID that has the most data and purchases associated with it, and use that one for your Apple ID. 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.       

When changing to the new ID, there may be some data loss, but you can minimize it. If syncing photos with iCloud, ensure Optimization is turned off in Settings/Your Name/iCloud/Photos and/or in Photos/Preferences/iCloud. Then make sure full resolution photos are on the device/computer. When signing out of iCloud, if asked whether you want to retain data, choose yes. Messages conversations will be lost if they are addressed to the ID. See the article below for other places that the old ID should be removed. See Winston Churchill's response in the below discussion.

 How to switch Apple IDs on your iPhone or iPad.      

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

How to transfer all files from one iCloud account to another.