Bike/frame size is important.

THere are no nerd bikes or riders.

GET A HELMET. Even if you have to buy a used one at a yard sale until you can getone that fits you.

You should be able to straddle the bike (if it's a man's model) without hitting the frame. I think you may have a 'beach comber' model?

You can adjust the handlebars and seat to your frame. To check the seat prop the bike up against a wall, stand back and look at the level of the seat.
It should be horizontal. Get the handlebars adjusted - If you have the straight or longhorn models, so your forearms are pretty level with the ground. Your body weight should be split between the seat and bars. If you lean too far forward your shoulders and neck will get tired from shifting your weight back and forth as you pedal, trying to get going and keeping your momentum.

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Fingerless gloves and shoes?

Even if you think you look funny or dumb, be prepared.

Gloves will protect your hands from road rash should you tip over and shoes with a stiff sole are a good idea. Your feet will thank you! As you pedal, your heel takes the stress of the 'push'. The pedal pushes your arch up and your foot flexes to keep it centered, you also stretch the ligaments and tendons of your forefoot, not a good thing after long rides.

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Also, get some pepper spray for pesky five year olds and dogs!