Before removing Apple ID from work MacBook

I have a work MacBook that my Apple ID and iCloud is attached to (this has been my only computer for two years). I have work files and personal files on this computer. Everything‘s organized and separate but still under the same iCloud account.

I recently gotten a new MacBook to be my own personal computer.

What is the best way to keep my personal files on my Apple ID iCloud account so that I have them on my new personal computer?

Also, how do I keep my work files on my work computer if I want to remove my Apple ID from my work computer?