As the owner of a Sharepoint site, you can grant people access to this share. To do this, do the following:

1. Go to the Sharepoint site.
2. Click the gear in the top right
3. Select "Site Permissions.

4. Click "Invite People"

5. Click "Add members to group"

6. Click "Add members

7. Type the name of the person you want to grant access.

8. Hit Save.