Hey, Yukiyoroi!
Sorry to hear that you are unable to access the Club. In order to troubleshoot this please uninstall Uplay and redownload it from: https://ubisoftconnect.com/en-US/
Once installed please try to access the Club again.
Thank you. The new Connect app is a major upgrade from the one I had (which was so old it didn't show the Store, Ubisoft+, or Discover tabs). I'm not sure what difference ithe new Connect app made in the game, but now when I click on the club link in the game menu I get a browser and menu options for store, forums, support, etc.