Are you talking about rules at junctions? They're different in every country as well as whether you drive on the left (RHS car) or drive on the right (LHS car).
In the UK, we drive on the left with right-hand steering cars.
If I recall correctly from my theory test, which was nearly two years ago ... at an unmarked junction with no traffic lights, no one has priority. Most junctions, however, are minor roads crossing a major road, so they are marked so that traffic on the major road has priority.
At traffic lights, you go when you have a green light. If you have a green circle, rather than a green arrow, you do not have sole right of way. For example, you may be about to turn right (across the flow of traffic) and have to wait for the people coming the other way to finish before you can actually go across. However, if you had the green arrow, your way would be clear and you could go straight over.
At a roundabout, you give way to those already on the roundabout, i.e. coming from the right.
I have a question for those who drive on the right. I've heard, many times, comments that 'it would be impossible to handle a manual gearbox/stick shift with my left hand'. I have actually found the opposite: I would hate to be controlling the steering of the car with just my left hand all the time. Gear manoeuvres are easy; keeping the car straight requires stronger muscles. I usually rest my left, rather than my right, when driving. Do you agree with the statement about it being hard to handle gearboxes with your left hand?
If you believe everything you read, better not read.