Creating a range of password protected pages - not sure where to start

A client wants to sell some online courses - all the booking and payment is done somewhere else.

What she wants is a page and directory that is password protected with a username and password - she won’t go in to the Manager to create these herself - is there a way for me to create a batch of accounts - say 10 at a time, that I could send to her. As she sells, she pass details to the individual and crosses through that account.

I guess its groups and permissions - i don’t really know where to start - any pointers please?

Thanks, David