A Microsoft file hosting and synchronization service.
By itself, renewing a subscription to Microsoft 365 or a subscription for additional storage in OneDrive doesn't cause any loss of files. If you are missing files, there's more to this incident than what you have told us. Do you have additional information to share that might help to explain what happened to your files? If not, we can try our best guesses, or you can show your computer to a professional, which is what I recommend.
There's no such things as a OneDrive account. OneDrive is a feature of a Microsoft account. When you renew a subscription to Microsoft 365, or when you renew a subscription for additonal storage, the storage that you receive is added to the OneDrive of the Microsoft account that you used to renew. It won't be added to the OneDrive of any other Microsoft account