Many people get workouts from magazines, or by copying people around them. Many exercises that are given in the magazines are not remotely functional or effective, and do not take each individual's biomechanical differences, injuries, and goals into account. Copying people around you is also risky as most people out there (including people who look fit) work out with very poor form or do exercises that are dangerous and/or ineffective.
Unless you are 100% confident that you know what you are doing, I would work with a certified professional at least once. You will learn how to work out so you will safely achieve your goals, and at a faster rate than if you were starting out from scratch on your own.
It's an investment to your health and will help with your future workouts and goals. But when you are seeking help, do your research and make sure that professional has the qualifications and background to help you achieve YOUR goals as there are many people out there who are masquerading as personal trainers.
Internationally Certified Personal Trainer and Nutrition Coach