HOW DO I UPDATE IT IM STUCK IN A RLY OLD VERSION

there are two ways: you either reinstall the game or you can install the itch.io app and it will update the game automatically

If you are on windows, then you can copy and paste your savings from C:\Users\(your windows user)\AppData\LocalLow\Fishlicka\Juice Galaxy\saves into another folder and then delete the juice-world-windows-64bit folder and reinstall the game then you can put back the saves into the folder.