In course 2 the stop was “2% from the entry.” That's fine for practice, but the market has no reason to turn exactly there. The chart does have such places — levels.
An example. Support is at $100, the price has come down to it, and you buy at $101. The idea: the floor will hold. The stop goes at $98.5, just below the floor with a small buffer. While the price stays above the floor, the idea is alive. Once it drops below, the idea is gone, and the stop closes the trade.