I am confused with adding people to jira cloud

[mat jung]

I am feeling confused about jira cloud, people and projects.

I am owner of two jira sublevel domains ( one production, one development) and a member of a third jira sublevel domain.

If I login into one sublevel domain and click on people, I see a menu Your Teams with people from another sublevel domain. How come? How can I hide people / teams who do not belong to a sublevel domain?

In Jira Quickstart - Invite your teammates it is unclear, how to invite them.

Am I supposed to add people into a sublevel domain or into a project?

Am I supposed to put people into a team, into a project, into a group or into what?

How do I find out if an invited person accepted / rejected the invitation?

Can I customize the invitation?

If I click on People -> manage users - I see the people who belong to a sublevel domain.

By the way, what is the jira terminology for sublevel domain? Is that a space or work space?

There are a lot of buttons Ask the Community.

Dear Community - do you want to answer the same questions again and again? Isn't there a list with previously asked questions around?

admin/EditApplicationProperties!default.jspa

"Enables users to contact administrators by displaying an email form. Can be used with or without the custom message below."

Who is the "contact administrator"? An employee from Atlassian - or do I have that priviledge?

"On a free plan, you can only add people using your site's administration settings. Upgrade your plan to better control who can access this project."

Great that I could upgrade it, but how about a link to "site administration".

Let me guess site = sub level domain

If someone has status "has site access", what does it mean?

Can that person create projects and hit the Create button, do I need to put that person into group confluence-users and jira-software-users first?

I am feeling lost in the cloud.

Sorry for writing down my frustration. Feeling better.