I just bought a unicycle, a vehicle that touches down with just the one wheel.
I have ridden a unicycle. It looks so hard to do.
It is not easy.  I wanted one after watching the pros at circuses, festivals and street performers.
Oh that must have been pretty cool. Who invented the unicycle?
There were two patents for them published.  One in 1869 and one in 1881
Would there happen to be different types of unicycles?
Just like everything, there are varieties.  They even created off road unicycles in the 1980s.  Those guys are nuts!
Do the circus performers and pros do tricks on the unicycles?
Oh yes, they try to ride over obstacles without the rider touching the ground.  Not an easy skill to master
That sounds pretty gnarly. They are so hard to ride.