Will the beginning of any control system be an open loop?
Hm. Well, "open-loop" describes a particular type of control system, specifically one without any feedback. For example, think of time-scheduled devices, such as a washing machine. The washing machine simply is given an input (turn of a knob or a press of a buton to start) and then washes for a given amount of time and stops. It does not use any feedback (any output signal, such as how clean the clothes is) to determine how long to wash.
On the other hand, a close-loop control system, like a thermostat, measures its output (in this case the temperature of the air) to reduce its deviation from the desired temperature.