i had one in college. learning to ride one beats the bejeezus out of the nose of the seat. you tend to fall forward and the nose takes the brunt of the hit. find one with a burly seat. unicycle seats are more like saddles or cradles versus the standard bike seat you typically see. i'm not sure they are interchangable.
i practiced in my dorm hallway where i could put my hands out and balance myself. i never did master it. i think i drank too much