Please specify for us: do you download and launch the game from an .exe file or are you using an itch-client?
The latest free version of the game is v0.33.2.5, so if you launch the game and in the main menu see anything older than that, then you're launching the wrong version.
It's pretty complicated, since we don't have official support for itch client.
Either it saves the save files just like the regular game would (%APPDATA%\Roaming\RenPy\ACADEMY34-v0.2.3) or it saves them in some sort of special itch folder (%APPDATA%\itch\apps).
You can try downloading the latest public release without using the itch app and check if the game will automatically find the saves.