Hi aratahikaru and welcome!
To test Jasonette very fast, the best is to install JASON app on your iOS device.
You can browse functions from here and in parallel you can start developing you own first script in jasonbase.com (don't forget to add a title to your script and click SAVE in jasonbase).
Once you have a script you want to test, simply enter its short key from the url (something like sJ3a) in the footer and click GO, it will load and keep your script in your list with the title of your script.
Click on this title to see your script in action (or nothing or error if it fails, it happens).