I have Metastock 7.21. This is my primary stock charting application. Gannalyst can read metastock data. It is a secondary tool. I use it basically to see the swings. Gann swing charts are unavailable in Metastock. (Here is a link to a lesson on how to trade using Gann swings : http://www.paritech.com/products/software/hottrader/hottrader_lesson/hottrader_lesson_4m.asp).
As for how to use the software, I would start with reading the help file, specifically "Introduction Tutorial - Using the Tools".
Regards,
Debraj