I just started learning to ride a unicycle 2 days ago(not too successfully I might add). Today I notice that when I was mounting it, when I pushed down on the pedal it would push down to the bottom but the wheel didn’t spin. Any ideas on what could be broken or if this is normal.
Welcome to the forums.
This sounds like the hub is broken. Can you give a more thorough description and maybe provide a photo?
If it is an old unicycle with cottered cranks you might be missing the cotter pin, otherwise your hub is probably broken.
thanks for the quick replies. its a brand new avenir 24". I’m currently at work so I can’t take any pics but theres nothing visibly wrong with it. Going to try to return it and buy a higher quality unicycle now that I know I enjoy it.
Welcome 
you should unmount the cranks from the hub and see if the hub is broken, or it coul be a crank issue, and if you are giving it back for the money and getting a beter unicycle you should look for what you ant to do, commuting"riding long distances" MUni"( mountine unicycling) " street" riding around town doing tricks and jumps) " flat" (just doing tricks on the asfalt as crank flips and such) or “trials” ( jumping on pellets or on rocks doing high jumps and falls" because you need to have an aim to know what to buy, because there are diferent unicycles and price ranges to pick from, and theres not a unicycle that will do it all.
if you have any question about what to get or what you want to do, just look or ask in the forums or PM me!
welcome to the forums and to the unicycle sport!