If you decide to replace your pedals, be careful! Left-hand pedals have a left-hand (reverse) thread. Right-hand pedals have a right-hand (normal) thread. Careful inspection of the pedals will reveal which one is which – one is marked L and the other R. If you force them into the wrong crank, you will damage the thread, and probably end up buying a new pair of cranks.

SPDs or clipless pedals

SPDs or clipless pedals which work with a cycling shoe with a cleat, which snaps into a receptacle on the pedal.  It's important to make sure your cleats stay tight (usually with an Allen key), and know how to adjust your pedals according to how quickly you'll need to release.