I'm a bit biased but https://liveblocks.io is great for that :)
If you know how to use React, that's pretty much all you need to know. It also includes some nice hooks to enable things like multiplayer undo/redo and live cursors.
The team even put a couple of interactive blog posts about that that you might find interesting: - https://liveblocks.io/blog/how-to-build-undo-redo-in-a-multi... - https://liveblocks.io/blog/how-to-animate-multiplayer-cursor...
Happy to answer any questions you may have!