[2022] Mods not showing up but shows that I'm subscribed on the Steam Workshop.

255710 is Cities: Skylines ID number on Steam, so any files with another number would be for other games you have.

For verifying the game files, right-click on the game in your Library, select Properties, select the tab Local Files, and click the button to "Verify integrity of game files..." - this usually takes a little while.