Hi there @JKM2, thanks for reaching out to us.
At first, I want to clarify that even if your account is converted to a Basic account, you don't lose access to private content and any shared folders you own.
Having said that, if you are a team admin and you wish to leave an active team which has other members in it, you:
- Can appoint someone else as the team admin, if there isn't another one already.
- Will have to ask another team admin to convert your account to an individual (Basic) one.
Do not worry, you won't lose access to the content that you'll get to keep.
Instead, your account will simply stop syncing if the storage limit is exceeded.
Once your account is converted to a Basic one, you can upgrade to a Plus account from this link.
I hope this helps, but let me know if you have any other questions. Cheers!