When I started experimenting with building apps on no-code platforms I built basically the same app each time. I was managing a payroll services company a few years ago and we ended up at one point needing to produce a web-based payroll entry program. I had a lot of experience planning and creating that application, so I decided that I would go with what I knew and try building that same app on each platform. That gave me a pretty good idea of how each platform worked, but it also limited the number of features I made use of - and that's why I've decided to use a different approach in the future.
One of the first small projects I looked at was a simple to-do list on Bubble. I was about to move on when I saw that Bubble had added some suggestions at the end of the tutorial about what you could add to expand on and improve on the app (see: https://manual.bubble.io/learning-bubble/more-features-for-your-to-do-app). I think that approach should allow you pretty much test all the features available on a particular no-code platform.
This approach may or may not work for you, but if you're looking over several platforms this could help you compare them and give you an idea of what's possible with each one.