To check how many credits you have left, you can click the little menu icon in the Copilot sidebar in an Office app and then ...
OneDrive offers a few options (there are 100GB and 200GB plans), but Google Drive and iCloud offer more. It's important to keep in mind that pricing isn't the only factor you should take into ...
OneDrive still powers the files experience, but more so as a user interface than having any integration with the cloud.