Give site manager to the person who runs the site and needs to write work entries, materials, and the rest of the log. Give crew to everyone who should document the day with notes and photos only.
There is one project manager on the account: the person who subscribed. They are the only role that can lock a day, export the PDF, invite people, and manage billing.
Team includes up to 10 people, counting you; each extra person is $4 a month. Solo is a single user.