Hi there. First-time poster here. Pretty new to bicycle maintenance as well.

I have a 20" Schwinn Hinge that I use to commute to school every day, about three miles one way. Recently the pedal on the left crank was bent down in the crank's socket (still not sure how this happened!) and I had to unscrew it and screw it back in very carefully to make it fit back in straight. It's slowly bending out of place again so I know I'm going to have to replace the arm before I have a catastrophic failure. Don't want to have to take the bus on short notice, haha.

I tried searching for a guide on how to find a replacement part for this, but had no luck. How do I know what kind of crank to buy? Specifically, the specifications so it matches the rest of the crankset. I linked to the specs of the bike earlier in my post, but it's not specific about what the sizes are.

Any ideas? I'm only looking to replace the crank itself for now until I can get a new crankset.