Hi, thanks for reaching out! Please allow me to assist you.
On the OneDrive client, you can have multiple work or school accounts, but only one Personal OneDrive account.
https://support.microsoft.com/office/how-to-add...
To separate your personal settings and OneDrive, I would suggest to consider OneDrive for Business. This will create a separate work account.
https://www.microsoft.com/microsoft-365/onedriv...
When it comes to Windows backup and sync, choose to use your personal Microsoft account for it.
https://support.microsoft.com/windows/about-win...
Please let me know if I can help you further!