Welcome to the TR community!
Plan Builder will start by building you out a plan that “meets you” where you’ve been at in terms of volume/intensity lately. Plan Builder then creates a plan for you that will be sustainable based on your recent training.
If you haven’t been doing longer rides in a bit, Plan Builder won’t have those longer sessions plugged in by default.
As you move through your plan, you can “Check” your plan’s volume (instructions here). If you handle the training stress of your original plan well, Plan Builder may increase your volume as you increase your fitness.
You can also schedule in longer rides manually by using Workout Alternates, TrainNow, or by browsing our Workout Library.
Finally, while long rides can be helpful in prepping for longer events, they aren’t totally necessary. Most of your fitness will come by targeting the energy systems you’ll be using the most during your Fondo through interval training. Long rides can still help you out with testing your equipment and nutrition strategies (plus they’re usually pretty fun!), but too many of them can derail the rest of your plan – especially if they pile on too much extra training stress. The following article has more info if you’re interested:
Hope that helps clear things up – feel free to let us know if you have any additional questions!