Every SharePoint site has 3 default groups:
- Visitors - assigned Read permission level
- Members - assigned Edit permission level
- Owners - assigned Full Control permission level
To directly add users to your SharePoint Site
Click on Settings (gear) > Site Settings
1. Under Users and Permissions click Site Permissions
2. Click on the Add members button and select Add members to this group
3. Click Add members and then enter the email address(es) of those you want to share with (as you type, suggested email address(es) appear below--click on one to add it),
4. Click Save