This is a great article from Adobe's Scott MacDonald on how to create a Tree component and also offers a solid primer on the Touch UI. However, if you don't feel like creating all of the Nodes manually, the AEM enablement team has created the XML for the Touch UI dialog box, available here:
Dropbox - touch-dialog
https://helpx.adobe.com/experience-manager/using/creating-touchui-tree.html
In addition, the article references JSP code but if you are interested in the Sightly code, the AEM enablement team created that here.
Dropbox - jsp:sightly
As always, if you have any specific questions feel free to set up office hours through the LMS or attend an instructor session.
