How to Share a SharePoint Site with Users
A SharePoint site without any users is a bit pointless. You can share your site in a number of different ways. For a Team Site, the easiest way is to click the Share Your Site tile on the Pop-Up app on the main page. You can also share your site by clicking the Share button at the top of the screen.
If you don’t have permission to share access to the site, then you won’t see the Share button. SharePoint automatically removes it.
In general with SharePoint, if you read about something and it doesn’t match what you see on your site, then it is probably one of two issues: First, you might not have the right permissions for that particular feature; or second, the feature might not be activated or configured for your site.
You must also have the right permissions to activate the feature you’re looking for.
If you use SharePoint Online, you have the ability to share a site with people outside your organization. This ability can be turned on and off by your administrator. If your site has the ability, you can just click the Share button, and then enter the e-mail address of the person with which you want to share to send that person an invitation link.