Hello,
Thanks for reaching out and for your interest in CryptPad!
It's not possible to do what you describe within the same team easily. You could create a Shared Folder and enable the Access List to only allow the people you want to access the and its content.
However, it's rarely a viable long-term solution. You have to maintain the list of people accessing stuff, not super practical. Maybe you'd end up in a better situation by create another team? With only the members you want?
On our flagship instance, https://cryptpad.fr, free accounts can create as much as 5 different teams. Paid accounts are limited to 10.
Hope this helps!