If you haven't been in a full service bike store lately, there are more bicycle variations available today than you can ever imagine.
My suggestion is to acquire a bike - any bike. Ride it around for awhile. Try to mix up your routes. Every time that you ride, make a mental list of what you like and what you hate about your bike AND where and how you are riding. The experience will greatly reduce your cluelessness.
__________________
My greatest fear is all of my kids standing around my coffin and talking about "how sensible" dad was.