How To Share Documents & Folders
Share a document or a folder
Within the one drive area you will have a list of folders and documents. You can share these by clicking on the share icon with the arrow on)
Then select Sharing Settings
and choose the permissions you want as per the below: 
- Choose if you want to: allow editing, if you want the link to expire, if you want users to use a password to access and if you want to block users from downloading what's on the site.
- Add a message if you want.
- Select Send
You can also access a tutorial from Microsoft here on this topic