Users and roles
Account → Users invites people to this account. Owners manage billing and the HubSpot connection; admins manage everything else; members compose. Agencies invite their own staff here; client accounts have their own users.
Removing someone ends their access to this account and signs them out of it. Their login stays: they can be invited again, or create an account of their own. Only a person can delete their own user, under Profile, Delete my user; it is refused while they own an account (transfer ownership or delete the account first).
Signing up is two steps: your login (name, email, password), then your account (company or agency, name, domain). After that, a short setup asks about you (mobile, two-factor), the account and the address.
If you sign in and you are not part of an account yet, mxAURA shows a short home page with the invitations sent to your email and a Create account button. You can accept or decline an invitation there, in addition to the email link. Until you join or create an account you can reach your profile and nothing else: no campaigns, no settings, no API keys, no connected tools.