What are the best ways to remove personal files from my MacBook?

Depends. Is the work Mac yours or your company's? Is it your company?

If you have different Apple IDs on each Mac then they will have different calendars, notes reminders, etc. and you might have to buy apps again for the new Apple ID. You might be able to set up sharing for some of these.

I don't know what you mean by turning off functions.

It's not clear what you are trying to achieve and why you want to separate work and personal stuff. I'm not saying it's a bad idea or a good idea but until you decide exactly what you want to do then you can't really be advised on how to do it. For example, Contacts; if you have different Apple IDs on the Work and Personal Mac then their contacts will be different sets of contacts. Not a problem - but what about your phone? If it's an iPhone you can only synch Contacts with one Apple ID - i.e. one Mac. Are you going to have two phones? ( you might be able to frig it with CardDav, but I don't know).

I work for myself, I have a number of clients and I use the same Mac for work and personal stuff. It would be a nightmare maintaining separate Contacts, Calendars, ToDos, not to mention lugging two Macs everywhere. I have personal and work calendars in the Calendar App but they're all in one place - otherwise it'd be a pain to manage and I'd have to invite myself to things if I had different Macs.

OK. Have you got a technical question?

If not keeping completely separate, usual is using two Apple Accounts and two macOS logins, though there are other ways including running guests in a virtual machine, or dual-booting.