I use the free trials for Proffesional, and it's only me second day. The Geometry pallet doesn't add any shape when I use it! I followed the tutorials and nothing happened. I tried changing transparency and color, still nothing.
I'll presume you have successfully activated a Caedium license according to "What is product activation?".
Do you have a active View Window rather than the Start-up web page in Caedium?
Rather than Drag and Drop tools from the Geometry Tool Palette, make sure the View Window is active and double-left-click on a tool, e.g., Volumes->Box. Does this create geometry in your View Window?
If you are still having problems please share a screenshot using Dropbox or something similar so I can take a look. Use our Contact form to share the file's location.
Also what version of Caedium are you using (Help->About) and on what platform (e.g., Windows 7, 64-bit)?