UL aircraft had their own evolution; originating from hang gliders. So they logically progressed from weight shift to 2 axis and then 3 axis. There are many trike designs that still use weight shift.
So first ask yourself: do I want to fly a trike or something more airplane like. Then research what is out there.
There are many factors....cost, time, storage, engine type, materials, etc. Do you want to build or buy?
Find the nearest EAA chapter, join it. Chapters are a great resource for info and help. Figure out what works best for you.
Take a look at the ultralights section at Barnstormers.com and you should get a feel for the market place.
Take your time don’t rush into it. Good luck!!!