You only need a proper warmup before workouts that have a medium to maximum intensity level. 15 minutes of relaxed jogging and one to three short increases in speed are ideal preparation for your training.
We generally recommend that beginners start off slowly during their runs. In this case, an additional warmup is not required.
You can also do a cooldown after a workout with maximum intensity. Light jogging for 5 to 10 minutes is sufficient for this.