Supposing you are driving your trains at the right side, you need at least one extra signal per side. You need to protect driving into the converging trackt at the point (switch) and add a signal at the red arrow. Do this at both stations of course. Then you will be able to run 2 trains simultaneously. When you drop extra signals at even interval on both sides of the dubble track, you will be able to run a multitude of trains.
You can let trains run on the left side, even though the signals are placed on the right side of the corresponding track.
You just have to place the traffic on the right side of the left track, put the signal in oneway-mode and your trains drive on the left side of the track. The language on the screen is German, but since I described, what I’ve done, you should’ve no problem to understand it and can learn some German Words 😉