You are going to burn calories doing this. Eat something!
Biking is hot. Not, like, sexy, (well, whatever butters your muffin) but all those calories you are burning? BURNT THINGS MAKE HEAT. You know how with babies you put on an extra layer? With biking, you should probably take off a layer. Except your ears and hands. You can put on a extra layer there.
Pants and bikes are natural enemies. Your bike hates your pants, and your pants hate your bike. Keep them away from each other. Biking stores will sell you velcro with reflector strips on them, which if you are me, you will immediately lose: these are for strapping down your pant-cuffs. When you lose them, you may be happy to know you can use those leg-warmers that never really were as stylish as everyone was telling you to the same effect. You will look like an enormous dork, but you're already biking, so really, what have you got to lose?
Gears are confusing, so I will explain. Lower gears are for biking into the wind. Higher gears are for when your feet are going around too fast and keep flying off your pedals. Some people may tell you that lower gears are for going uphill, but why are you going uphill? What's so important at the top of the hill? Absolutely nothing is that fucking important. Biking uphill is for chumps and people on anabolic steroids. You can go around hills. The wind, on the other hand, is guaranteed to swing around and oppose you no matter where you go.
You probably need to add 20% to Google Maps' time estimate. The time given is for expert bikers, which is ridiculous, because expert bikers know better than to use Google Maps. Google Maps doesn't really understand how bikes work. You can totally go down that alleyway, over that grassy margin, and through that pedestrian overpass, and you can definitely go around that hill. (See point 4.) Once you figure out a route that takes advantage of this, you can take the 20% back off.
You can get all over town on a dirt-cheap bike. You can only go about three blocks on a cheap bike lock. (I don't really know about good bike locks, but go on youtube. People there will explain this to you at somewhat terrifying length.)