Stress can be managed in many ways.
Very often, simply talking to someone about you feel can alleviate the stress. This could be in the form of offloading worries to a loved one or explaining to your manager why you will be unable to meet a deadline. This is a simple, yet effective, way to manage stress.
Relaxation techniques such as deep breathing or meditation can be a useful way to combat stress as it allows you to take time to relax, reflect on the problems internally and maybe come up with some solutions. Again this is easy to do but can also be very effective.
Going on a stress management course can help you to learn techniques to manage your stress more effectively. Although it may be useful in the long term, this would not help with any immediate stresses as you would have to wait until the date of the training.