Every state has their own set of traffic laws. In addition, many cities have bicycling related ordinances. However, the traffic laws are generally similar across the US. Basically, you are required to obey all traffic signs and right of way rules as if you were a motorist. This means you are required to come to a full stop at all stop signs, obey traffic lights etc. You also are probably required to ride 'as far to the right as practicable'.
Localities vary as to whether you can ride on sidewalks, interstate highways, and other limited access roads. It's best to check the codes for your state. Indiana probably has their laws online. You might try a search for 'bicycle' to get statutes applying to cyclists.
In some areas police do not strictly enforce traffic laws with cyclists. In others they do. Sometimes it depends on the policeman and what else he may be doing. A cop responding to another call will probably not be looking for traffic violations for example.