WOW! Good for you for getting out there and riding! Your health is really going to improve.
Keep riding... and then ride some more... BUT... PLEASE GET A HELMET ASAP! Basically, you really should NOT ride WITHOUT A HELMET!
Point in case: My boyfriend had just gotten his pretty new Trek 1500 (aka: $1,200 road bike)... and he was riding along a bike path. What could go wrong? There aren't any cars... so he should be just fine. YEA! RIGHT?! Basically, he over-corrected missing someone coming head on... and he crashed into this cemet railing for the bridge he was near. He DEMOLISHED his bike. Seriously. It was a month old and nothing could be saved. He separated his shoulder, and had these horrilbe gashes on his HEAD! His helmet was crushed, but his head was intact. His helmet saved him from serious injury. And, then he went and about a $1,500 road bike. GO BUY A HELMET TODAY! *Said with concern and love*
With that said... it won't be long before we will suck you in with your "hybrid", "road", bike talk. You will start to learn all about cycling and then you will be TEMPTED to jump head-first into it... with your credit card close behind.
Good luck and keep riding!
"Life is not a journey to the grave with the intention of arriving safely in a pretty and well preserved body, but rather, to skid in broadside thoroughly used-up, totally worn out, and loudly proclaiming: WOW WHAT A RIDE!!!!"