1. Disable Steam Cloud: Alt click Terraria and go to Properties then in the general tab uncheck the box "Keep game saves in the Steam Cloud for Terraria"
2. if you do not have a Microsoft account you would need to create one. To the bottom right of your taskbar you will see a cloud icon, click that and go to OneDrive settings, accounts, choose folders. There you should deselect your Documents folder, if you cannot deselect it go 1 more in and deselect the My Games folder. If you do not see it in your taskbar you can find it in your Start menu, simply click the windows icon on the left of your taskbar and look for OneDrive open it up, it’ll open a folder just right click an empty space and click “settings” should be able to find accounts then choose folder from there.