Thank you for posting to the Telerik Developer Forums.
I am not sure which tutorial exactly you are following and what are the difficulties you are encountering. Below I will try to explain how to continue without any impediments with the Telerik Platform interactive tutorials.
You can easily restart the tutorial and start from scratch using the navigation pane of the tutorial screen on your left. Please, refer to the screenshot attached.
In case you need to examine the error in the code, start the simulator and press F12 on your keyboard which will open the developer console of the browser and you will be able to see any errors thrown or debug the app by placing breakpoints.
If you'd like to check your code against the completed tutorials, here is the link to them:
Let me know if this works for you.
In regard to your other inquiry, I believe that our product specialists will get in touch with you as soon as possible.