Welcome to the TR community! 
As @mcneese.chad and @Clubs17 mentioned, it sounds like it would be worth searching for sessions at higher Workout Levels to get you started.
You could use Workout Alternates to search for higher-level workouts that your plan suggests you do. You could also manually search our Workout Library and use the search filters to find training sessions that align with what you’ve been doing lately for each zone.
As an example, 4x12min at Threshold sounds like a workout such as Byers Peak -2, which is a Threshold 4.9. Searching for Threshold workouts at Workout Level 5 (or higher, if that’s where you’re at!) would get you on the right track.
As you complete workouts at a given Workout Level, your personal Progression Levels will update to reflect what the software will then know you’re capable of. After that, Adaptive Training will take the reins and you won’t have to do as much manual tweaking – you’ll start getting workouts that line up with your updated Progression Levels.
Check out the links Chad posted if you want to dive deeper into the details of how all that works. Hopefully this info is helpful! Feel free to let us know if you have any additional questions. 