You can only use the 20 included workouts in the app, nothing else so ride now will not work, no workouts ONLY the 20. I tried to make that as clear as possible after other people were confused, see below.
A creative workout builder can design and execute an unlimited number of workout variations in real time as they are riding in our app even in the free version by merging workouts together and using the + - and skip feature with auto-extend turned on. Really I bet you could build any of the 20k workouts we have while riding by merging and skipping in real time, it just would require some focus and creative thinking.
You can download the workouts but TP does not have an upload feature so you must upload to a Zwift folder on your PC (lots of info of this with google) and restart or start zwift.
With the free version you also don’t get sync to strava but you can download the finished activity and upload it yourself.
There is no easy way to get custom workouts into TP other than via paid TrainerDay, so pushing to Garmin from TP is not a viable solution unless you buy a TP training plan for example. Paid TD is the cheapest and easiest way that I know of to get workouts on to Garmin.
Does that help and make it clearer?