I want to know how to share data between two of my places, but I need to know how to do this. I can’t do this with datastores, because datastores store data locally on the place / game. I also want to know how to do this for free.
Can anyone tell me where to start / how to do this?
Have you tried out using global Datastores instead of the regular Datastores? Also, assuming what you mean by ‘Player Data’ being the player instance inside Players, I do not believe it is possible to share that instance across other servers.
Instead, what you could do is use is Messaging Service to signal other servers the necessary details of the player.
If you want to share data from the same game but in a diferent place, jsut access to the datastore service and get the player’s data!
About other games i dont know. But i hope this helps 
You will need an external website to handle data if you want to share data between different universes/games. Theres no other way, and don’t expect it to be free. Free hosting always has drawbacks, either being rate limited, limited storage, unreliable service, etc.
Google sheets and trello are also not databases, don’t treat them like one.
Ah, what a shame. I spent countless hours trying to access trello wth roblox, and it did not work, and now that you said it… I basically just wasted my time.
I mean, YOU CAN use trello or google sheets… until your game gets 1,000 players and you exceed their limits and what not, then you’ll be out of luck. It’s also just really bad design to use services like them, that were not meant for it. Proper databases would be something like amazon dynamodb instances, though it isn’t free. Anything proper isn’t going to be free.
If you wanna save some time, I’d suggest you use Firebase Real-Time Database for your global database system. There is already a great module created for this so most of the work is already done for you. I have been using this for the same purpose and it works just fine. Didnt run into any errors. If you have a large player base, you might end up paying for the service, but its not really that expensive imo. You can check it out here