Amplenote offers an adequate set of features for sharing notes that can be edited by others. This help page will cover the high points as of September 2020.
Click the usual note actions menu in the upper-right corner of Amplenote, and then pick "Add Collaborators":
Getting ready to add collaborators
This will take you to the "Invite Amplenote users to collaborate" dialog:
Collaborator dialog: showing frequent collaborators
When possible, we'll give you a list of suggested users, based on who you've collaborated with before.
When the "Edit" toggle is active, the collaborator will be granted edit access to the note. Otherwise, if only "Share" is active, the note will be shared in read-only mode.
Click the "Include a message" link if you would like us to send the collaborators a message in the email where they are notified about the newly shared note.
After a note is shared, you'll see the number of people who have received the note next to the Share icon in the note header. You can click here to adjust the share settings:
Share icon shows how many have access, and re-opens collaboration dialog
That icon (or this menu option) take you back to the collaboration dialog, where you can adjust the permissions of a user who had access, or ditch them altogether:
Controlling access granted to a user who currently has access
If you delete a shared note, anyone you shared it with will still be able to view it unless you remove them from the shared note prior to deleting.
The tags that you have attached to a note are not received when a note is shared. The recipient has the opportunity to make their own decisions as to how they would like to file the note within their tag hierarchy.
This is subject to change with the pending addition of Inline Tags.
When a note has been shared, it will also show up as such in your notes list, if you're in three-pane mode: