Almost all of the laws that apply to motor vehicles also apply to bicycles, with a few exceptions. For example, it’s against the law to obstruct traffic, ride recklessly, or wear headphones while riding your bike on public roads (although state law does allow cyclists to use one earphone for safety purposes). Cyclists are advised to plan their routes carefully and avoid high-speed, narrow streets whenever possible to increase their chances of arriving at their destination safely.
If you are riding on a road with a dedicated bike lane, keep in the lane until it’s safe to move into the roadway to pass other vehicles or pedestrians. You may exit a bike lane only when it’s reasonably safe, and you should give a clear signal before doing so. (CVC 21208)
Unlike motor vehicles, bicycles do not come equipped with turn signals or brake lights, so it’s important to use hand signals to let other road users know what you intend to do. To signal a left turn, extend your left arm and hand horizontally away from your body. To signal a right turn, bend your right arm at the elbow and extend it vertically away from your body.
Almost all states and cities prohibit bicycles from riding on sidewalks, but some do allow it if you’re going slowly enough to not interfere with pedestrians. It’s a good idea to check with your local Department of Transportation or city government to find out what the rules are.