Welcome fuuryu! To answer your question, wearing a specific type of Kimono to an event depends on the age, marital status, and the event itself. For example: your 3 and 7 year old daughter is going to be dressed in her first Furisode for Sichigosan. When she's 20 Years Old, she's going to go to her coming of age day in another furisode. It used to be black furisode with crests were for very important/cermonial occasions.
You'll probably wear your last Furisode when you're over a specific age and/or you get married. For example, I'm 28 years old but not married - so I would wear a Tomesode.
As for patterns, generally Kimon patterns are based on the season.
This is a seasonal guide to Kanzashi, but it's a start on what kind pattens that might be used on Kimono during each season...