Consider the illustration of a fictitious junction. Applying the KCL gives you...
I1 + I2 + I3 = I4 + I5
The KCL corresponds to the mass conservation law of physics. It simply states that no current can spontaneously arise or disappear.
However, the KCL is not able to tell how the current is divided or why. Nevertheless, the KCL is indispensable to analyze complex circuits. But more on that later.
In the next experiment, you apply the KCL to your circuit...