Every LimeSurvey Cloud plan has exactly one primary admin: the person who created the account at account.limesurvey.org. That account holds the survey site, the plan and the billing. The primary admin also logs in to the survey site as its administrator, with the admin password of the survey site.
On the Your account page, the primary admin can:
Colleagues don't get access to the account page. The primary admin adds them to the survey site instead, where they work with surveys, participants and results under their own users. Click the Manage administrators icon in the sidebar of the workspace, or open Configuration > Users > User management in the top bar. What each person may do depends on their permissions. See How permissions work.
That depends on your plan: 1 on the free and Basic plans, 3 on Expert, 5 to 10 on Business. See Subscription plans.
Download them on the Billing history tab of your account page and pass them on. See Billing, payment and invoices.