The most important fact is that on your first lesson you will get to drive the car. Before you do that however your instructor will make sure that you’re comfortable in your seat and the mirrors are setup to enable you to drive the car.
After that they will take you through all the major controls of the car, what each one does and how you use it. After that the instructor will take you through the move and stop briefing in which they will explain and, if you wish, demonstrate how to move the car and stop the car safely.
On your second or third lesson your instructor will start to explain how junctions work. They will explain a basic routine for you to follow that will become the building blocks to every junction you approach.
Below is a video of turning left from a major road to a minor road:
Once you find that you are consistently doing this routine on approach to all junctions you will feel that you’re calm and in control of the car. This will then allow you to make good and safe decisions at all junctions.
Like everything in driving though you need to be able to adapt, this routine is a great starting place but every junction is different each time you go there. Don’t be a robot, use your common sense and react to what you see in front of you.