New Apple ID

Apologies if this has already been asked by someone. I setup my Apple ID many years ago using my works email address. I'm going to retire soon and need to change my ID. to my personal email address. My current ID is used for iTunes, iCloud and the downloading of a number of apps, some free some paid for.

1. What will happen to my data and the apps I have downloaded
2. Is it better change my ID or just create an new Apple ID and start afresh
3. I have a Macbook Pro, iPad Air 4th gen and an iPhone 12 Pro which are all synced. What will be the impact on them if I change my ID or if I create a new Apple ID

Kind regards - Frank