Welcome aboard! Glad you're having fun.

Most of the speed bumps in my area are pretty flat and wide, and it's no trouble riding over them on a bike (in fact you can drive over them at 25 mph). For the ones that are higher and require you to slow way down in a car, you can still ride over them but if you're uncertain and still getting used to bike, it's fine to go around them too. You probably would want to lift your butt a bit off the saddle when you ride over them for comfort.

Also I hate to send you back to the store but if your new helmet hit the post or the ground when you crashed, you should replace it. Helmets are designed to only take one impact and after that it's safest to replace them.

Good luck!!