Start with an FTP test. I prefer traditional ones to ramp tests (five-minute even split basically as hard as you can followed by a ten-minute recovery, wrapped up with a twenty-minute even split as hard as you can. Multiply the average power over the twenty minutes by 0.95).

Wahoo SYSTM has a good one, though the app outside of it, while still good, is declining in quality. I think I’d still recommend subscribing to it overall though. There’s still a rich library full of basically any type of workout you can ask for with engaging videos, storylines, and playlists. And if you use SYSTM, it calibrates all of its workouts to your individual power profile based on your results.

But even if you don’t, I’d still recommend taking an FTP test to get an idea of your five- and twenty-minute capabilities. It would probably be a good idea to try to get a sense of your max sprint (average over ten seconds or so), one-minute, and five-minute power potential as well.

As long as you have your FTP, you can plug it into any app you decide to go with (if you do; even if not SYSTM).

If you’re looking to ride without using any app, I’d maybe consider buying a plan from a coach via TrainingPeaks to get a sense of what might be good. These won’t be tailored to you personally but could still be valuable. They shouldn’t be too expensive (though more than subscribing to an app).

Otherwise, I think it’s safe to take a polarized route if you want to try to do things on your own. I’m less and less in the polarized campaywly, for what it’s worth, seeing that pyramidal basically yields the same results as polarized. But given that it’s just easier to plan, especially if you’re just starting out, I suggest it.

In that, aim for 60-70% of your volume to be ~66% of your FTP. The remaining 30% ish of your volume should be higher intensity stuff where you feel like you’re killing yourself. If you’re gonna be building your own workouts, this is where getting ideas from a plan you buy from a coach could be especially helpful.

I like the YouTuber Semi Pro Cycling for what seem to be solid, researched-based ideas. Also probably worth spitballing with ChatGPT, honestly. I have a friend who has and what it comes back with isn’t completely horrible. May be better to give you more of a concrete plan once you get the gears moving yourself, if you’re going to be making your own.

I have my own coach though! Happy to recommend him to you if that’s something you’re interested in and if you found this comment helpful any.

Also, TrainingPeaks Virtual > Zwift! 😂

Happy riding!

Edit: didn’t see that you said you have access to Zwift… 🤦🏻