Need help on a note system like a dream youve had before and other 4slug games

In games like these:
a dream youve had before
your last thoughts at the end of time
players can write a note or put up an image on a wall, I know how to make a gui so the player can write and place these notes on walls but I dont know how to make them save and show for other players in different servers.

I know that I need to use the Data Store Service but I am not very familiar with using it.
If anyone with more experience could help me I would appreciate it alot.

Okay so how I would tackle this is make a poster on a wall where players could upload a image or place down text. Then when the player leaves in data store you save their image ID they uploaded or their text.

please let me know if you find out anything!